Hydrogen fueling systems and methods

ABSTRACT

According to aspects, hydrogen fueling systems and methods are provided, including vehicle-to-vehicle communication techniques, hydrogen cooling techniques and/or hydrogen dispenser control techniques that facilitate improving aspects of a hydrogen fueling station.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 120 and is acontinuation (CON) of U.S. application Ser. No. 17/374,268, entitled“HYDROGEN FUELING SYSTEMS AND METHODS” filed on Jul. 13, 2021, whichclaims priority under 35 U.S.C. § 119 to U.S. Provisional ApplicationSer. No. 63/195435, filed Jun. 1, 2021 and titled HYDROGEN FUELINGSYSTEMS AND METHODS, to U.S. Provisional Application Ser. No. 63/131953,filed Dec. 30, 2020 and titled VEHICLE COMMUNICATION IN HYDROGEN GASDISPENSING SYSTEMS, to U.S. Provisional Application Ser. No. 63/057163,filed Jul. 27, 2020 and titled VEHICLE TO DISPENSER COMMUNICATIONMETHODS AND APPARATUS, to U.S. Provisional Application Ser. No.63/057150, filed Jul. 27, 2020 and titled HYDROGEN DISPENSER METHODS ANDAPPARATUS, to U.S. Provisional Application Ser. No. 63/057159, filedJul. 27, 2020 and titled HYDROGEN COOLING METHODS AND APPARATUS, to U.S.Provisional Application Ser. No. 63/051181, filed Jul. 13, 2020 andtitled VEHICLE TO DISPENSER COMMUNICATION METHODS AND APPARATUS, eachapplication of which is herein incorporated by reference in itsentirety.

BACKGROUND

Hydrogen fuel cell vehicles (HFCV) are emerging as a zero-emissionalternative to internal combustion engine vehicles. HFCVs operate byproviding compressed hydrogen to a fuel cell stack which converts thehydrogen into electricity to drive an electric motor. Similar tointernal combustion engine vehicles, HFCVs are equipped with fuel tanksthat must be refilled periodically. To safely and/or efficientlydispense hydrogen gas to a vehicle, a number of parameters are typicallyrequired, including tank volume, measured pressure and measuredtemperature. Conventionally, fueling parameters are communicated betweena hydrogen gas dispenser and the vehicle using the set of protocolsspecified by the Infrared Data Association (IrDA) for opticalline-of-sight (LOS) wireless communication. IrDA provides acommunication scheme with a low bit error rate suitable forcommunication between a dispenser on a vehicle.

HFCVs often have fuel tanks that utilize Compressed Hydrogen StorageSystems (CHSS), which are very sensitive to high temperatures. Manycurrent fueling protocols adopted by hydrogen refueling stations requiregaseous hydrogen fuel to be cooled between −40° C. to −17.5° C. prior todispending to the vehicle in order to ensure the vehicle's CHSS maintaintheir bulk gas temperatures below 85° C. regardless of ambient orprevious driving conditions. Current fueling stations typically employone of two types of heat exchangers to cool hydrogen gas for dispensinginto the fuel tank of an HFCV.

A first conventional heat exchanger includes a large cast aluminum block(typically, in a range between 600-1000 kg) that is buried underneaththe fuel dispenser and that is cooled to very low temperatures by arefrigeration or condenser unit (also referred to as a “chiller” or“cooler”) via refrigeration tubing about which the aluminum block wascast. The aluminum block is also cast with stainless steel tubingthrough which hydrogen gas is passed to cool the hydrogen gas beforedispensing the hydrogen into the fuel tank of the vehicle. Specifically,heat exchange between the hydrogen gas flowing through thestainless-steel tubing and the chilled aluminum block cools the hydrogengas to the low temperatures needed for HFCV dispensing.

A second conventional heat exchanger employs a diffusion-bonded heatexchanger that uses a conventional plate-to-plate configuration that isdesigned for high pressure. The diffusion-bonded heat exchanger isfluidly coupled to a reservoir of coolant that is brought down to thelow temperatures needed for hydrogen gas dispensing by a largerefrigeration unit (chiller). Chilled coolant from the reservoir ispassed through the diffusion-bonded heat exchanger along with hydrogengas to cool the hydrogen gas before dispensing into the fuel tank of theHFCV.

SUMMARY

Some embodiments include a hydrogen gas fueling station comprising aroadside unit positioned at the fueling station and configured tocommunicate with a first on-board unit associated with a first vehicle,and a first dispenser communicatively coupled to the roadside unit andconfigured to dispense hydrogen gas via a first nozzle, the firstdispenser configured to provide first nozzle information correspondingto the first nozzle to the first vehicle when the first vehicle hasengaged with the first nozzle, wherein the roadside unit is configuredto receive feedback from the first vehicle responsive to the firstnozzle identification information via a first connection establishedwith the first on-board unit.

Some embodiments include method of performing vehicle-to-nozzle pairingcomprising establishing a first connection between a roadside unitpositioned at a fueling station and a first on-board unit associatedwith a first vehicle, engaging a first nozzle of a first dispenser witha first vehicle, providing first nozzle information corresponding to thefirst nozzle to the first vehicle, receiving feedback from the firstvehicle responsive to the first nozzle identification information viathe first connection, and associating the first connection with thefirst nozzle based on the received feedback.

Some embodiments include a fueling station comprising a roadside unitpositioned at the fueling station and configured to communicate with aplurality of on-board units associated with respective vehicles via arespective wireless connection established between the roadside unit andeach of the plurality of on-board units, and at least one controllerconfigured to process fueling information received via each respectivewireless connection and configured to cause at least one action to beperformed based on the received fueling information.

Some embodiments include a method comprising establishing a wirelessconnection between a roadside unit positioned at a fueling station andeach of a plurality of on-board units associated with respectivevehicles, receiving fueling information via each wireless connection,and performing at least one action at the fueling station in response tothe received fueling information.

Some embodiments includes fueling station comprising a roadside unitpositioned at the fueling station and configured to communicate with aplurality of on-board units associated with respective vehicles via arespective wireless connection between the roadside unit and each of theplurality of on-board units, and at least one controller coupled to theroadside unit, the at least one controller configured to process fuelinginformation received via each respective wireless connection andconfigured to cause at least one action to be performed based on anexpected refueling demand determined from the received fuelinginformation.

Some embodiments include a method comprising establishing a wirelessconnection between a roadside unit positioned at a fueling station andeach of a plurality of on-board units associated with respectivevehicles, receiving fueling information via each wireless connection,and performing at least one action at the fueling station based on anexpected refueling demand determined from the received fuelinginformation.

Some embodiments include a fueling station comprising a roadside unitpositioned at the fueling station and configured to communicate with afirst on-board unit associated with a first vehicle via a first wirelessconnection established between the roadside unit and the on-board unit,and at least one controller configured to receive a nozzle reservationrequest via the first wireless connection and configured to negotiate anozzle reservation via the first wireless connection.

Some embodiments include a method comprising establishing a wirelessconnection between a roadside unit positioned at a fueling station and afirst on-board unit associated with a first vehicle, receiving a nozzlereservation request via the first wireless connection, and negotiating anozzle reservation via the first wireless connection.

Some embodiments include a fueling station comprising a first roadsideunit positioned at the fueling station and configured to communicatewith a plurality of on-board units associated with respective vehiclesvia a respective wireless connection between the roadside unit and eachof the plurality of on-board units, and at least one controller coupledto the first roadside unit, the at least one controller configured toprocess fueling information received from the roadside unit via eachrespective wireless connection, determine status information indicativeof refueling capability of the fueling station, and provide the statusinformation to at least one of the plurality of on-board units via therespective wireless connection.

Some embodiments include a method comprising establishing a wirelessconnection between a roadside unit positioned at a fueling station andeach of a plurality of on-board units associated with respectivevehicles, receiving fueling information received via each respectivewireless connection, determining status information indicative ofrefueling capability of the fueling station, and providing the statusinformation to at least one of the plurality of on-board units via therespective wireless connection.

Some embodiments include a hydrogen cooling system comprising alarge-volume reservoir for holding coolant, a small-capacityrefrigeration unit coupled to the large-volume reservoir to reduce atemperature of coolant held in the large-volume reservoir, and a heatexchanger configured to thermally couple coolant held by thelarge-volume reservoir to hydrogen gas flowing through the heatexchanger via heat exchange with the coolant.

Some embodiments include a hydrogen cooling system comprising alarge-volume reservoir for holding coolant, a small-capacityrefrigeration unit fluidly coupled to the large-volume reservoir toreduce the temperature of coolant held in the large-volume reservoir,and a heat exchanger fluidly coupled to the large-volume reservoir and ahydrogen gas source, the heat exchanger configured to cool hydrogen gasfrom the hydrogen gas source using coolant from the large-volumereservoir.

Some embodiments include a hydrogen fueling system comprising a firstdispenser configured to dispense hydrogen gas via a first nozzle, asecond dispenser configured to dispense hydrogen gas via a secondnozzle, a large-volume reservoir for holding coolant, a small-capacityrefrigeration unit coupled to the large-volume reservoir to reduce atemperature of coolant held in the large-volume reservoir, a first heatexchanger coupled to the large-volume reservoir and configured to chillhydrogen gas via heat transfer with coolant held by the large-volumereservoir and provide chilled hydrogen gas to the first dispenser fordispensing via the first nozzle, and a second heat exchanger coupled tothe large-volume reservoir and configured to chill hydrogen gas via heattransfer with coolant held by the large-volume reservoir and providechilled hydrogen gas to the second dispenser for dispensing via thesecond nozzle.

Some embodiments include a hydrogen fueling system comprising a firstdispenser configured to dispense hydrogen gas via a first nozzle, asecond dispenser configure to dispense hydrogen gas via a second nozzle,a large-volume reservoir for holding coolant, a small-capacityrefrigeration unit coupled to the large-volume reservoir to reduce atemperature of coolant held in the large-volume reservoir, and a firstheat exchanger coupled to the large-volume reservoir and configured tochill hydrogen gas via heat transfer with coolant held by thelarge-volume reservoir and provide chilled hydrogen gas to the firstdispenser for dispensing via the first nozzle and to the seconddispenser for dispensing via the second nozzle.

Some embodiments include a hydrogen fueling system comprising a firstdispenser configured to dispense hydrogen gas via a first nozzle, asecond dispenser configure to dispense hydrogen gas via a second nozzle,a first large-volume reservoir for holding coolant, a secondlarge-volume reservoir for holding coolant, a small-capacityrefrigeration unit coupled to the first large-volume reservoir and thesecond large-volume reservoir to reduce a temperature of coolant held inthe first large-volume reservoir and the second large-volume reservoir,a first heat exchanger coupled to the large-volume reservoir andconfigured to chill hydrogen gas via heat transfer with coolant held thefirst large-volume reservoir and provide chilled hydrogen gas to thefirst dispenser for dispensing via the first nozzle, and a second heatexchanger coupled to the second large-volume reservoir and configured tochill hydrogen gas via heat transfer with coolant held by the secondlarge-volume reservoir and provide chilled hydrogen gas to the seconddispenser for dispensing via the second nozzle.

Some embodiments include a hydrogen cooling system comprising a firstreservoir comprising a first tank configured to hold first coolantcomprising at least one phase-change material, a refrigeration unitcoupled to the first reservoir to chill the first coolant to cause thephase-change material held by the first tank to change from a firststate to a second state, and a first heat exchanger configured tothermally couple the first coolant held by the first reservoir tohydrogen gas flowing through the heat exchanger via heat exchange withthe first coolant.

Some embodiments include a hydrogen cooling system comprising a firstreservoir comprising a first tank configured to hold first coolantcomprising at least one phase change material, a second reservoircomprising second tank configured to hold second coolant, arefrigeration unit coupled to the first reservoir to chill the at leastone phase change material to cause the phase change material to changefrom a first state to a second state, and coupled to the secondreservoir to chill the second coolant, and a first heat exchangerconfigured to thermally couple the first coolant and hydrogen gasflowing through the heat exchanger to chill the hydrogen gas to a firsttemperature via heat exchange with the first coolant, and a second heatexchanger configured to thermally couple the second coolant and thehydrogen gas chilled to the first temperature to chill the hydrogen gasto a second temperature via heat exchange with the second coolant and toprovide the chilled hydrogen gas to at least one first dispenser.

Some embodiments include a hydrogen fueling system comprising a firstdispenser configured to dispense hydrogen gas via a first nozzle, asecond dispenser configured to dispense hydrogen gas via a secondnozzle, a large-volume reservoir for holding coolant, a singlesmall-capacity refrigeration unit fluidly coupled to the large-volumereservoir to reduce the temperature of coolant held in the large-volumereservoir, a first heat exchanger fluidly coupled to the large-volumereservoir and a hydrogen gas source, the first heat exchanger configuredto provide cooled hydrogen gas for dispensing by the first dispenser viathe first nozzle, and a second heat exchanger fluidly coupled to thelarge-volume reservoir and a hydrogen gas source, the heat exchangerconfigured to provide cooled hydrogen gas for dispensing by the seconddispenser via the second nozzle.

Some embodiments include a hydrogen fueling system comprising a firstdispenser configured to dispense hydrogen gas via a first nozzle, asecond dispenser configure to dispense hydrogen gas via a second nozzle,a large-volume reservoir for holding coolant, a small-capacityrefrigeration unit fluidly coupled to the large-volume reservoir toreduce the temperature of coolant held in the large-volume reservoir,and a first heat exchanger fluidly coupled to the large-volume reservoirand a hydrogen gas source, the first heat exchanger configured toprovide cooled hydrogen gas to the first dispenser for dispensing viathe first nozzle and to the second dispenser for dispensing via thesecond nozzle.

Some embodiments include a hydrogen fueling system comprising a firstdispenser configured to dispense hydrogen gas via a first nozzle, asecond dispenser configure to dispense hydrogen gas via a second nozzle,a first large-volume reservoir for holding coolant, a second largevolume reservoir for holding coolant, a small-capacity refrigerationunit fluidly coupled to the first large-volume reservoir and the secondlarge-volume reservoir to reduce the temperature of coolant held in thefirst and second large-volume reservoirs, a first heat exchanger fluidlycoupled to the first large-volume reservoir and a hydrogen gas source,the first heat exchanger configured to provide cooled hydrogen gas fordispensing by the first dispenser via the first nozzle, and a secondheat exchanger fluidly coupled to the second large-volume reservoir anda hydrogen gas source, the heat exchanger configured to provide cooledhydrogen gas for dispensing by the second dispenser via the secondnozzle.

Some embodiments include a hydrogen cooling system comprising a firstreservoir comprising a first tank holding at least one phase changematerial, a refrigeration unit coupled to the first reservoir to chillthe at least one phase change material to cause the phase changematerial held by the first tank to change from a first state to a secondstate, and a first heat exchanger to receive hydrogen from a hydrogengas source and provide hydrogen gas to at least one first dispenser, thefirst heat exchanger coupled to the first reservoir to chill thehydrogen gas from the hydrogen gas source to provide chilled hydrogen tothe at least one first dispenser.

Some embodiments include a hydrogen cooling system comprising a firstreservoir comprising a first tank configured to hold first coolantcomprising at least one phase-change material, a second reservoircomprising a second tank configured to hold second coolant, arefrigeration unit coupled to the first reservoir to chill the at leastone phase-change material to cause the at least one phase-changematerial to change from a first state to a second state, and coupled tothe second reservoir to chill the second coolant, a first heat exchangerconfigured to thermally couple the first coolant and hydrogen gasflowing through the first heat exchanger to chill the hydrogen gas to afirst temperature via heat exchange with the first coolant, and a secondheat exchanger configured to thermally couple the second coolant and thehydrogen gas chilled to the first temperature to chill the hydrogen gasto a second temperature via heat exchange with the second coolant and toprovide the chilled hydrogen gas to at least one first dispenser.

Some embodiments include a hydrogen cooling system comprising a firstreservoir comprising a first tank holding at least one phase changematerial, a second reservoir comprising second tank holding at least onenon-phase change coolant, a refrigeration unit coupled to the firstreservoir to chill the at least one phase change material to cause thephase change material held by the first tank to change from a firststate to a second state, and coupled to the second reservoir to chillthe at least one non-phase change coolant, a first heat exchanger toreceive hydrogen from a hydrogen gas source, the first heat exchangercoupled to the first reservoir to chill the hydrogen gas to a firsttemperature via heat exchange with the at least one phase changematerial, and a second heat exchanger to receive the hydrogen gas at thefirst temperature from the first heat exchanger, the second heatexchanger coupled to the second reservoir to chill the hydrogen gas viaheat exchange with the at least one non-phase change material to chillthe hydrogen gas to a second temperature and provide the hydrogen gas toat least one first dispenser.

Some embodiments include an annular heat exchanger comprising a shellhaving a coolant inlet and a coolant outlet, at least one coilcomprising nickel alloy tubing concentrically arranged within the shell,the at least one coil having a hydrogen inlet and a hydrogen outlet, anda plurality of copper fins brazed to the at least one nickel alloy coilusing silver or silver alloy, wherein the annular heat exchanger isconfigured to chill hydrogen gas that is caused to flow through the atleast one coil via the hydrogen inlet and the hydrogen outlet by heatexchange with coolant that is caused to circulate through the shell viathe coolant inlet and the coolant outlet.

Some embodiments include annular heat exchanger comprising a shellhaving a coolant inlet and a coolant outlet, at least one coilcomprising tubing concentrically arranged within the shell, the tubinghaving a wall thickness between 0.03 and 0.06 inches and a lengthbetween 30 and 50 feet, the at least one coil further comprising ahydrogen inlet and a hydrogen outlet and having between 20 and 35 turns,and a plurality of fins attached to the at least one coil, wherein theannular heat exchanger is configured to chill hydrogen gas that iscaused to flow through the at least one coil via the hydrogen inlet andthe hydrogen outlet via heat exchange with coolant that is caused tocirculate through the shell via the coolant inlet and the coolantoutlet.

Some embodiments include a hydrogen gas dispenser configured to receivehydrogen gas from a hydrogen gas supply and provide the hydrogen gas toa fuel tank of a vehicle during a fueling event, the hydrogen gasdispenser comprising at least one nozzle configured to engage with thefuel tank to dispense hydrogen gas to the fuel tank during the fuelingevent, a valve bank comprising a plurality of fixed-size orifice valvesarranged in parallel, the bank configured to receive hydrogen gas fromthe hydrogen gas supply and to deliver hydrogen gas passing through oneor more of the plurality of fixed-size orifice valves that have beenopened, and a dispenser controller coupled to the bank and configured toselectively open or close the plurality of fixed-size orifice valves todeliver gas at desired target pressures and/or target flow rates to theat least one nozzle.

Some embodiments include a hydrogen gas dispenser configured to receivehydrogen gas from a hydrogen gas supply and provide the hydrogen gas toa fuel tank of a vehicle during a fueling event, the hydrogen gasdispenser comprising at least one nozzle configured to engage with thefuel tank to dispense hydrogen gas to the fuel tank during the fuelingevent, a variable-size valve comprising a valve stem that when rotatedchanges a size of the valve opening, the variable-size valve coupled toreceive hydrogen gas from the hydrogen gas such that changing the sizeof the valve opening results in a change in a flow rate of hydrogen gaspassing through the valve opening, a direct drive servo motor coupled tothe valve stem of the variable-size valve, the direct drive servo motorconfigured to rotate the valve stem to change the size of the valveopening, wherein one rotation of the direct drive servo motor results inone rotation of the valve stem, and a dispenser controller coupled tothe direct drive servo motor and configured to cause the direct driveservo motor to rotate to change the size of the valve opening to providehydrogen gas at desired flow rates based on target pressures and/ortarget flow rates of the fuel tank of the vehicle during the fuelingevent.

Some embodiments include coaxial tubing for piping hydrogen gas betweencomponents of a hydrogen fueling station, the coaxial tubing comprisinginner tubing configured to allow hydrogen gas to be piped between one ormore components of the hydrogen fueling station, middle tubing arrangedconcentrically about the inner tubing such that when phase changematerial is contained in the middle tubing, the phase change material ispositioned to thermally couple to hydrogen gas flowing through the innertubing, and outer tubing arranged concentrically about the middle tubingsuch that when coolant is conveyed through the outer tubing, the coolantthermally couples to the phase-change material when present.

Some embodiments include a hydrogen fueling system comprising coaxialtubing comprising inner tubing configured to allow hydrogen gas to bepiped between one or more components of the hydrogen fueling station,middle tubing arranged concentrically about the inner tubing so that aphase change material contained in the middle tubing thermally couplesto hydrogen gas flowing through the inner tubing, and outer tubingarranged concentrically about the middle such that when coolant isconveyed through the outer tubing, the coolant thermally couples to thephase-change material contained in the middle tubing, and a chillersystem configured to chill coolant to a temperature sufficient to causea state transition of the phase-change material, the chiller systemcoupled to the coaxial tubing to convey chilled coolant through theouter tubing to cause the state transition of the phase-change materialcontained in the middle tubing.

BRIEF DESCRIPTION OF DRAWINGS

Various aspects and embodiments of the disclosed technology will bedescribed with reference to the following figures. It should beappreciated that the figures are not necessarily drawn to scale. Itemsappearing in multiple figures are indicated by the same reference numberin all the figures in which they appear.

FIG. 1 illustrates a block diagram of an exemplary hydrogen gasdispensing system including a fueling station and a vehiclecommunicatively coupled to the fueling station, in accordance with someembodiments;

FIG. 2A illustrates a plurality of vehicles in-range and out-of-range ofa fueling station, in accordance with some embodiments;

FIG. 2B illustrates a plurality of vehicles within a zone ofcommunication of a fueling station, in accordance with some embodiments;

FIG. 3 illustrates a vehicle hopping technique, in accordance with someembodiments;

FIG. 4A illustrates an exemplary communication sequence between afueling station and one or more vehicles, in accordance with someembodiments;

FIG. 4B illustrates an exemplary method of taking action at a fuelingstation based on fueling information received via a controller areanetwork, in accordance with some embodiments;

FIG. 4C illustrates an exemplary method of performing nozzle reservationvia a controller area network, in accordance with some embodiments;

FIG. 5 illustrates a block diagram of an exemplary hydrogen gasdispensing system including a fueling station and a plurality ofvehicles communicatively coupled to the fueling station, in accordancewith some embodiments;

FIG. 6 illustrates a method of performing vehicle-to-nozzle pairing, inaccordance with some embodiments;

FIG. 7 illustrates a method of performing vehicle-to-nozzle pairingcomprising electrically transmitting a nozzle identification to avehicle, in accordance with some embodiments;

FIG. 8 illustrates a block diagram of an exemplary gas dispensing systemusing the vehicle-to-nozzle pairing method illustrated in FIG. 7, inaccordance with some embodiments;

FIG. 9 illustrates a method of performing vehicle-to-nozzle pairingcomprising delivering a flow signature to a vehicle, in accordance withsome embodiments, in accordance with some embodiments;

FIG. 10 illustrates a method of performing vehicle-to-nozzle pairingcomprising electrically transmitting a nozzle identification anddelivering a flow signature to a vehicle, in accordance with someembodiments;

FIG. 11 illustrates a hydrogen cooling system comprising a refrigerationunit, coolant reservoir and high UA heat exchanger, in accordance withsome embodiments;

FIG. 12 illustrates an exemplary process for maintaining and recoveringa target temperature of coolant in a hydrogen cooling system configuredfor hydrogen gas refueling, in accordance with some embodiments;

FIG. 13 is a plot of recovery times as a function of refrigeration unit(chiller) capacity at three different ambient temperatures using a100-gallon tank as the coolant reservoir;

FIGS. 14A-E illustrate aspects of an annular high UA heat exchanger forhydrogen refueling using a shell-and-tube configuration, in accordancewith some embodiments;

FIG. 15 illustrates a coil for an annular high UA heat exchanger thathas been finned to increase the heat transfer efficiency of the coil, inaccordance with some embodiments;

FIGS. 16A-F illustrate different configurations for an annular high UAheat exchanger, in accordance with some embodiments;

FIG. 17 illustrates a hydrogen cooling system comprising a refrigerationunit having an integrated coolant reservoir, in accordance with someembodiments;

FIG. 18 illustrates a hydrogen cooling system configuration in which arefrigeration unit provides cooling to a coolant reservoir shared bymultiple dispensers, each dispenser coupled to a respective heatexchanger, in accordance with some embodiments;

FIG. 19 illustrates a hydrogen cooling system configuration in which arefrigeration unit provides cooling to a coolant reservoir shared bymultiple dispensers that share a heat exchanger, in accordance with someembodiments;

FIG. 20 illustrates a hydrogen cooling system configuration in which arefrigeration unit provides cooling to multiple coolant reservoirs andheat exchangers coupled to respective dispensers, in accordance withsome embodiments;

FIG. 21 illustrates a hydrogen cooling system utilizing phase changematerial (PCM) to increase the thermal energy capacity of a coolantreservoir, in accordance with some embodiments;

FIG. 22 illustrates a dual-stage hydrogen cooling system comprising abulk PCM reservoir and a polishing reservoir, in accordance with someembodiments;

FIG. 23 illustrates an annular heat exchanger configured to hold PCM forhydrogen cooling, in accordance with some embodiments;

FIG. 24 illustrates a hydrogen cooling system utilizing annular heatexchanger configured to hold PCM for hydrogen cooling, in accordancewith some embodiments;

FIG. 25 illustrates a hydrogen cooling system comprising a refrigerationunit have an integrated coolant reservoir configured to contain both PCMand conventional coolant, in accordance with some embodiments;

FIG. 26A illustrates coaxial tubing that integrates PCM and conventionalcoolant to provide hydrogen cooling, in accordance with someembodiments;

FIG. 26B illustrates an exemplary hydrogen fueling system employing thecoaxial tubing illustrated in FIG. 26A;

FIG. 27 illustrates the pressure profile of an exemplary fuelingprotocol;

FIG. 28 illustrates a hydrogen dispenser comprising a bank of fixed-sizeorifice valves to control the flow rate of hydrogen gas, in accordancewith some embodiments;

FIG. 29 illustrates a method for performing a fueling event employing abank of fixed-size orifice, in accordance with some embodiments;

FIG. 30 illustrates a dual-nozzle dispenser employing a bank offixed-size orifice, in accordance with some embodiments;

FIG. 31 illustrates a hydrogen dispenser comprising a flow control valvehaving a direct drive servo motor paired with a variable-size orificevalve, in accordance with some embodiments;

FIG. 32 illustrates a method for performing a fueling event employing aflow control valve having a direct drive servo motor paired with avariable-size orifice valve, in accordance with some embodiments; and

FIGS. 33A and 33B illustrate views of a flow control valve having adirect drive servo motor paired with a variable-size orifice valve, inaccordance with some embodiments.

DETAILED DESCRIPTION

Existing communication between a vehicle and a hydrogen fueling stationis generally limited to a LOS link between the vehicle and the hydrogendispenser, conventionally implemented using a one-way IrDA connectionestablished between an infrared transmitter disposed near the vehicle'sfuel tank and an infrared receiver on the dispenser nozzle brought intoclose proximity when the nozzle is inserted into the vehicle's fueltank. Once this unidirectional communication link is established, thevehicle can transmit fueling parameters such as tank volume and currenttank conditions such as tank pressure and temperature. This conventionalapproach has a number of drawbacks recognized by the inventors,including limited bandwidth, unidirectionality, equipment reliabilityand cost (approximately $3K per nozzle), etc.

The inventors have recognized that vehicle-to-vehicle andvehicle-to-infrastructure communications, referred to as V2X, can beemployed to expand the communication capabilities between vehicles andhydrogen fueling stations to improve the refueling process in a numberof ways, including providing a higher bandwidth, bi-directionalcommunication channel capable of safely and securely exchanging a muchricher set of data between vehicles and fueling stations. According tosome embodiments, a vehicle is equipped with an on-board unit (OBU)configured to wirelessly communicate with a road-side unit (RSU) locatedat a fueling station to exchange, among other data, fueling parameters,status information on the fueling station, and the like.

The inventors have further developed techniques to determine whichvehicle is engaged with which nozzle at a fueling station, a processreferred to as vehicle-to-nozzle pairing. As discussed above,conventional systems employed an IrDA communication link between avehicle and a dispenser established between an IrDA transmitter disposedproximate the vehicle's fuel and tank and an IrDA receiver (typically acircular array of IrDA receivers) disposed on the nozzle dispenser.Because an IrDA link could only be established between a nozzle and thevehicle to which the nozzle was engaged, there was no ambiguity toresolve. However, in a V2X wireless network, a fueling station maycommunicate with numerous vehicles within a zone of communication of thefueling station. As a result, the fueling station typically needs toresolve which vehicle is engaged at a given nozzle prior to performing arefueling event. According to some embodiments, vehicle-to-nozzlepairing comprises providing nozzle information to a vehicle andreceiving feedback from the vehicle via a wireless connection (e.g., aV2X connection) in response to receiving the nozzle information via aV2X connection established between the fueling station and the vehicle.The feedback from the vehicle may be used to associate the nozzle withthe wireless connection to perform vehicle-to-nozzle pairing. Theinventors have also recognized the importance of allowing refuelingevents to be performed anonymously. To ensure that vehicle anonymity canbe maintained, the inventors have developed vehicle-to-nozzle pairingtechniques and refueling processes that do not require a vehicle toprovide information that identifies the vehicle or its operator,examples of which are described in further detail below.

Following below are further detailed descriptions of various conceptsrelated to, and embodiments of, vehicle communication systems andmethods for facilitating refueling of hydrogen fuel cell vehicles. Itshould be appreciated that the embodiments described herein may beimplemented in any of numerous ways. Examples of specificimplementations are provided below for illustrative purposes only. Itshould be appreciated that the embodiments and the features/capabilitiesprovided may be used individually, all together, or in any combinationof two or more, as aspects of the technology described herein are notlimited in this respect.

FIG. 1 illustrates an exemplary system in which a fueling station isconfigured to communicate with a vehicle via wireless connectionestablished between the vehicle and the fueling station (e.g., viawireless V2X communication). System 1000 comprises a hydrogen fuel cellvehicle (HFVC) 1100 having at least one hydrogen fuel tank 1110 forstoring hydrogen gas used to power vehicle 1100. Vehicle 1100 is alsoequipped with an engine control module (ECM) 1160 (e.g., the vehicle'scomputer system) configured to obtain and monitor tank parameters of thehydrogen fuel tank(s) 1110. ECM 1160 is communicatively coupled toon-board unit (OBU) 1150 to allow wireless connections to be establishedbetween other vehicles and infrastructure, such as fueling station 1200.OBU 1150 includes one or more transceivers configured to transmit andreceive information wirelessly, for example, to communicate withroadside units, other OBUs, or any other devices configured for wirelesscommunications (e.g., mobile devices such as smart phones, navigationsystems, etc.). OBU 1150 is typically mounted in or on the car or maybe, alternatively, a mobile unit that can be positioned tocommunicatively couple with ECM 1160.

Fueling station 1200 comprises one or more hydrogen dispensers (e.g.,dispensers 1220 a, 1220 b, etc.) that dispense hydrogen fuel stored atand/or generated by fueling station 1200 via nozzles (e.g., nozzles 1225a, 1225 b, etc.) configured to engage with the fuel tank of an HFVC.Fueling station 1200 further comprises road-side unit (RSU) 1250(alternatively referred to as a wayside unit) configured to communicatewith vehicles equipped with an OBU (e.g., vehicle 1110 equipped with OBU1150). RSU 1250 also includes one or more transceivers configured totransmit and receive information wirelessly, for example, to communicatewith OBUs, other RSU's or any other devices configured for wirelesscommunications. RSU may be coupled to one or more controllers (e.g., oneor more processors, chips or chip sets, programmable logic controllers,systems-on-chip (SOC), etc.) configured to perform any one orcombination of vehicle communication techniques described herein. Asused herein, an RSU coupled to one or more controllers refers tocommunicative coupling between any of the controllers that are part ofthe RSU (e.g., on-unit processors, co-processors, PLC's, etc.) and/orany controllers that are communicatively coupled to the RSU (e.g., via awired or wireless communication link) at the fueling station.Furthermore, acts described herein as being performed by the RSU referto acts performed by the RSU and/or any controller to which the RSU iscoupled at the fueling station.

In the embodiment illustrated in FIG. 1, RSU 1250 is connected to anetwork at the fueling station (e.g., via a station PLC or networkswitch) to allow information exchange between RSU 1250 and thedispensers or other components of fueling station 1200. System 1000allows V2X communication between vehicle 1100 and fueling station 1200by establishing a wireless connection 1050 between OBU 1150 and RSU 1250over which information may be exchanged (e.g., fueling information suchas tank parameters, fuel availability, navigation information, paymentinformation, etc.).

According to some embodiments, V2X communication may be accomplishedusing the 5.9 GHz band allocated for dedicated short-range communication(DSRC). However, V2X may implemented in other ways such as via 4G, 5G,802.11x or using other suitable standards and/or protocols operating inthe same or different radio frequency bands, as the aspects are notlimited to any particular type of V2X communication. Wireless connection1050 does not require LOS so that fueling station 1200, via RSU 1250,can broadcast and/or exchange data with any OBU with which a connectionhas been established that is within range of RSU 1250 (e.g., within akilometer of the fueling station), or within a larger zone ofcommunication using a vehicle hopping technique, examples of which aredescribed in further detail below. It will be understood that fuelingstation is illustrated to show schematically a exemplary communicationcoupling of certain components of the fueling station, and that fuelingstation may include other components not illustrated, such as hydrogencooling systems (e.g., any of the exemplary hydrogen cooling systemsdescribed herein).

FIG. 2A illustrates an example environment in which RSU 1250 employed atfueling station 1200 can communicate with multiple vehicles (e.g.,vehicles 1100 a-1100 d) within range of the RSU (denoted schematicallyas range 1255). The range of the RSU will depend in part on thefrequency band used by the RSU to communicate with OBUs and regulatorylimits on that frequency band (e.g., power requirements limitingtransmission power, etc.), and may range from tens to hundreds of yardsto a kilometer or more. For example, according to some embodiments, RSUsand OBUs operate in the 5.9 GHz band (5.850-5.925 GHz band) allocatedfor DSRC, which can provide ranges on the order of a kilometer or more.According to some embodiments, OBUs and RSUs operate in the 5.9 GHz bandand are IEEE 1609, IEEE 802.11P and SAE J2735 compliant to facilitatesafe and secure exchange of information, further details of which arediscussed below.

In FIG. 2A, vehicles 1100 a-d are within range of RSU 1250 and cancommunicate with fueling station 1200 via the vehicle's respective OBU.Vehicle 1100 a, for example, may be at the fueling station and vehicles1100 b-d may be on the road or otherwise located within range of RSU1250. Typically, RSUs and OBUs exchange security information (e.g.,digitally signed certificates) to ensure that a given RSU and OBU areauthorized to exchange information and to authenticate the units at bothends of an exchange. Once a connection is established, the OBU cansecurely transmit tank information to the RSU such as tank volume,receptacle type, fueling commands, measure pressured and temperatureinformation and/or additional information about the vehicle (e.g.,location). Fueling station 1200 may transmit information to vehicles viaestablished connections between RSU 1250 and corresponding OBUs, such asstatus information regarding fuel availability, current wait times,fueling station location, etc. Additional information such as nozzlereservation information, navigation directions, etc., may be exchangedbetween the fueling station and the vehicles within range 1255, someexamples of which are discussed in further detail below.

According to some embodiments, establishing wireless connections andinformation exchange occur in a wireless access in vehicular environment(WAVE) that enables safe and secure communications between RSUs andOBUs, as discussed in further detail in Appendix A of U.S. ProvisionalApplication No. 63/131,953 ('953 Provisional) incorporated by referenceherein. Alternatively, or in addition to, other wireless communicationchannels and protocols may be used to establish connections and exchangeinformation between a fueling station and vehicles within a zone ofcommunication of the fueling station, some further examples of which aredescribed in Appendix A of the '953 Provisional.

The V2X environment illustrated in FIG. 2A may be used to establish acontroller area network (CAN) that allows fueling station 1200, via RSU1250, to communicate with multiple vehicles to obtain fueling parametersto inform a refueling event, collect data that facilitates predictingthe demand on the fueling station based on the fueling needs of vehiclesin the area, advise vehicles as to optimal timing and/or location for arefueling event, schedule a refueling event, etc. According to someembodiments, information exchanged via the CAN may be used to implementfurther functionality such as establishing automatic payment, providingnavigation guidance to fueling stations, transmitting fueling stationavailability, performing nozzle reservation, etc. For example, byevaluating tank information received from multiple in-range vehicles,fueling station can predict near-term demand and take one or moreactions at the fueling station in response, such as powering downcertain components of the fueling station (e.g., one or more componentsof a hydrogen cooling system) to save on power consumption, optimizingfilling of storage tanks to better handle expected fueling events, modelusage trends over time, establish peak demand, low demand and/or averagedemand metrics, etc., examples of which are described in further detailbelow.

According to some embodiments, a fueling station can communicate withvehicles that are out-of-range using a technique referred to herein asvehicle hopping by which messages between a fueling station and adestination vehicle may be routed through one or more intermediaryvehicles. For example, FIG. 3 schematically illustrates an exemplary CAN3000 comprising RSU 3250 at a fueling station 3200 and a plurality ofOBUs 3150 a-e deployed in respective vehicles 3100 a-e. In exemplary CAN3000, vehicle 3100 a is within range of RSU 3250 and has established adirect connection 3050 a with OBU 3150 a. Vehicles 3100 b and 3100 c arewithin range of vehicle 3100 a and direct connections 3050 b and 3050 chave been established between OBU 3150 a and OBUs 3150 b and 3150 c,respectively. Vehicle 3100 d is within range of vehicle 3100 b and adirect connection 3050 d has been established between OBU 3150 b and OBU3150 d. Similarly, vehicle 3100 e is withing range of vehicle 3100 c anddirection connection 3050 e has been established between OBU 3150 c andOBU 3150 e.

The direct connections established in CAN 3000 can be utilized toestablish an indirect connection between RSU 3250 and any of the OBUs inthe network, even those that are not within range of RSU 3250. Accordingto some embodiments, established direct connections are used aspass-throughs that enable RSU 3250 to establish an indirect connectionand thereafter route messages to and receive messages from any of theOBUs in the network via secure indirect connections. According to someembodiments, the communication protocol allows for the same securityfeatures to be used to ensure that indirect connections are also safeand secure (e.g., authorized and authenticated). After an indirectconnection is established, information can be exchanged via thisindirect connection by routing messages from vehicle to vehicle untilthe messages reach the specified destination.

By using vehicle hopping techniques, a fueling station can expand itszone of communication to exchange information with vehicles over a widergeographic area. For example, FIG. 2B illustrates the environmentillustrated in FIG. 2A in which vehicles 1100 a-d are within range 1255of RSU 1250 and wireless connections have been established between RSU1250 and each in-range vehicle. However, in the example schematicallyillustrated in FIG. 2B, the fueling station's zone of communication hasbeen expanded to allow RSU 1250 to exchange information without-of-range vehicles 1100 e-k using vehicle hopping techniques. Forexample, vehicles 1100 e and 1100 h are within range 1155 b of vehicle1100 b and direct connections are established between the OBUs of therespective vehicles. RSU 1250 can therefore establish an indirectconnection with vehicles 1100 e and 1100 h to transmit messages to andreceive messages from vehicles 1100 e and 1100 h by routing messagesthrough vehicle 1100 b. Similarly, vehicles 1100 i and 1100 j are withinrange 1155 e of vehicle 1100 e and direct connections are establishedbetween the OBUs of the respective vehicles and RSU 1250 can establishan indirect connection with vehicles 1100 i and 1100 j by vehiclehopping via vehicles 1100 b and 1100 e. Indirect connections canlikewise be established between RSU 1250 and vehicle 1100k by vehiclehopping from vehicle 1100 b to 1100 h, and between RSU 1250 vehicle 1100g and 1100 f by vehicle hopping via vehicle 1100 d. Thus, RSU 1250 cancommunicate with vehicles over a larger geographic area to expand thereach of fueling station 1200 (e.g., to form a larger CAN 2000), whichcan in turn improve the fueling station's ability to predict demand, canallow for a richer set of data to be obtained and/or may facilitateproviding services to a larger set of vehicles.

FIG. 4A illustrates an exemplary V2X communication sequence, inaccordance with some embodiments. Act 1410 comprises establishing awireless connection between an RSU located at a fueling station and anOBU of a vehicle. The connection process, also referred to herein asOBU/RSU pairing, may be initiated either by an OBU transmission receivedby the RSU or a via an RSU broadcast to OBUs within range. As discussedabove, in consideration of privacy considerations, some embodimentsemploy a communication architecture that allows for a secure connectionto be established (and subsequent messages to be exchanged) whilepreserving vehicle anonymity. For example, the above-mentioned WAVEarchitecture enables OBUs to establish authorized and authenticatedconnections with RSUs without requiring vehicle specific identificationinformation to be relayed to the fueling station. In this way, V2Xcommunications can be implemented while maintaining the privacy of thevehicle and its operator. According to some embodiments, upon theexpress or implied consent of the vehicle operator, informationidentifying the vehicle or the vehicle operator may be exchanged toallow certain services to be provided, such as automatic payment, nozzlereservation, etc., as discussed in further detail below.

Referring again to act 1410, to establish a wireless connection, an OBUand an RSU may exchange security information (e.g., signed digitalcertificates) confirming that the OBU and RSU are both authorized toestablish a connection and to authenticate the OBU and RSU devices. Thespecifics of the security information exchange will depend on theprotocol supporting the V2X communication. According to someembodiments, the V2X communication is a DSRC connection that complieswith, for example, IEEE 1609, IEEE 802.11P, SAE J2735 and/or any of theprotocols discussed in the '953 Provisional, and the securityinformation exchange is implemented via WAVE. Once a connection has beenestablished, data can be securely exchanged between the OBU and the RSU.As discussed above, some embodiments implement OBU/RSU pairing withoutrequiring vehicle or vehicle operator identification, thereby allowing asecure connection to be established and subsequent data exchange to beconducted while maintaining vehicle anonymity.

Act 1420 comprises exchanging data between the OBU and RSU over theestablished connection. In many conventional systems, informationexchange between a vehicle and a fueling station was limited to datathat could be transmitted over a IrDA link, which was limited not onlyin bandwidth but was also typically limited to unidirectionaltransmission of data from the vehicle to the dispenser nozzle.Establishing a V2X connection allows a richer set of information to beexchanged between a vehicle and a fueling station. For example,conventional IrDA links were sufficient for transmitting a minimum setof tank parameters needed by the fueling station to refuel the vehicle.According to some embodiments, a V2X connection has orders of magnitudehigher bandwidth, allowing for significantly more information to beexchanged bi-directionally between a fueling station and a vehicle.According to some embodiments, the RSU at a fueling station (e.g., RSU1250) may obtain tank information from the vehicle via the OBU over theestablished connection in real-time or near real-time.

As discussed above, some embodiments of a V2X communication system allowfor a many-to-many connections to be established (e.g., an RSU mayestablish a direct connection with a plurality of OBU within range ofthe RSU and/or may establish an indirect connection with one or moreout-of-range OBUs via vehicle hopping, as discussed above in connectionwith the exemplary embodiments illustrated in FIGS. 2A, 2B and 3).Accordingly, acts 1410 and 1420 may be repeated to establish secureconnections (direct or indirect) between a fueling station and multiplevehicles within a zone of communication of the RSU at the fuelingstation. As a result, information can be exchanged between a fuelingstation, via its RSU, and multiple vehicles that can be used to improveservice at the fueling station.

Act 1430 comprises performing one or more actions at the fueling stationbased at least in part on information exchanged between the RSU and oneor more OBUs associated with vehicles within the zone of communicationof the fueling station. According to some embodiments, a fueling stationmay obtain tank information from multiple vehicles in the vicinity andevaluate the information to perform one or more predictive actions atthe fueling station based on an expected demand at the fueling station.For example, information exchanged in act 1420 may indicate that severalvehicles in the vicinity are low on fuel and will likely need to refuelat the station in the near-term. In response, the fueling station mayevaluate the status of the fueling systems (e.g., assess the currentcapacity of the fueling station to deliver hydrogen fuel at certaintemperature levels). On the other hand, information exchanged in act1420 may suggest that there are no HFCVs in the area or that those thatare within range of the fueling station are not currently in need ofrefueling. Based on the predicted demand, fueling station 1200 can readyitself to best meet the predicted demand (e.g., power up or power downcertain components of the fueling station such as components of thehydrogen fueling station), alert vehicles in the vicinity as to status,wait times, etc., prepare for future fueling demands at the fuelingstation and/or identify trends or patterns in fueling demands tooptimize the ability of the fueling station to meet fueling demandsthroughout the day.

The inventors have developed a number of predictive techniques andresponsive operations to facilitate optimal fueling station performance(i.e., to maximize availability and/or minimize refueling times) tohandle changing fueling demands throughout the day, examples of whichare discussed in further detail below. Any one or combination ofoptimizations may be performed, including but not limited to, minimizingenergy consumption, maximizing fuel availability, reducing refuelingtimes, conducting dispenser scheduling (e.g., nozzle reservations),ascertaining demand trends, planning for peak demand hours, providingnavigation information to vehicles, redirecting vehicles to otherfueling stations, etc., examples of which are discussed in furtherdetail below.

The one or more actions performed at the fueling station may include afueling event in which the fueling station delivers fuel to the tank ofone of the vehicles. For example, the data exchanged in act 1420 mayinclude feedback from a vehicle to which a dispenser nozzle has beenengaged from which the fueling station performs vehicle-to-nozzlepairing, examples of which are described in connection with FIGS. 5-10below. The data exchanged in act 1420 may also include tank informationfrom the vehicle that the fueling station uses to refuel the vehicleafter the vehicle has been paired with the nozzle engaged with thevehicle's fuel tank. Act 1440 comprises disconnecting the RSU and theOBU, which may be performed with or without a fueling event with thevehicle. For example, the RSU and an OBU may disconnect after thecorresponding vehicle has refueled, or the RSU and an OBU may disconnectwhen the vehicle drives out-of-range or out of the zone of communicationof the RSU without the vehicle having come to and/or refueled at thefueling station. In the latter case, for example, tank information maybe obtained from a vehicle in act 1420 indicating that the vehicle has afull tank and the fueling station may use this information to performone or more predictive actions and may subsequently disconnect with theOBU when the vehicle drives out of range.

FIG. 5 illustrates a system 5000 comprising a fueling station 2200configured to refuel HFCVs and communicate with vehicles within a zoneof communication of the fueling station. At an exemplary point in time,a first vehicle 1100 a may be located at fueling station 2200 prior to afueling event and a plurality of vehicles including vehicles 1100 b and1100 c may be located within a zone of communication of fueling station2200. Fueling station 2200 includes RSU 2250, which may be similar to orthe same as RSU 1250 described in connection with FIG. 1 (e.g., an RSUconfigured to communicate with OBUs associated with vehicles within azone of communication of the RSU). In the example illustrated in FIG. 5,wireless connections 2050 a, 2050 b and 2050 c are established betweenRSU 2250 and OBUs of respective vehicles 1100 a, 1100 b and 1100 c.

Fueling station 2200 comprises a first dispenser 2220 a and a seconddispenser 2220 b configured to dispense hydrogen gas via a first nozzle2225 a and second nozzle 2225 b, respectively. While exemplarydispensers 2220 a and 2220 b are shown having a single nozzle, one orboth of dispensers 2220 a and 2220 b may include multiple nozzles viawhich hydrogen gas may be dispensed. Furthermore, while exemplaryfueling station 2200 is illustrated as including two dispensers, someembodiments include fewer or additional dispensers. For example, afueling station may include one single-nozzle or multi-nozzle dispenseror may include multiple single-nozzle or multi-nozzle dispensers, as theaspects are not limited to any particular configuration of dispensersand nozzles.

In the embodiment illustrated in FIG. 5, dispensers 2220 a-b arecommunicatively coupled to RSU 2250 via station network component 2210(which may be the same as or similar to network component 1210 describedin connection with FIG. 1). In the embodiment illustrated in FIG. 5,dispensers 2220 a-b are fluidly coupled to hydrogen storage component2205 that stores hydrogen gas to be dispensed by the dispensers throughtheir respective nozzles. According to some embodiments, the dispensersmay also include hydrogen storage within the dispenser or may be astandalone appliance that produces, stores and dispenses hydrogen gas ina self-contained dispenser appliance, some examples of which aredescribed in U.S. Pat. No. 10,236,522 titled “Hydrogen Gas DispensingSystems and Methods,” which is herein incorporated by reference in itsentirety.

Wireless connections (e.g., wireless connections 2050 a, 2050 b and 2050c) may be established between RSU 2250 and the respective OBU of anyvehicle within the zone of communication of the fueling station. Forexample, wireless connections 2050 a and 2050 b may be directconnections to vehicles 1100 a and 1100 b and wireless connection 2050 cmay be an indirect connection to vehicle 1100 c via vehicle 1100 b usingvehicle hopping techniques. Once a wireless connection has beenestablished, information can be exchanged between vehicles and thevarious components of the fueling station including, but not limited to,any one or combination of fueling information (e.g., tank parameters),fueling station status (e.g., hydrogen gas availability, predicted filltimes, etc.), navigation information, payment information, etc. Inexemplary system 5000, vehicle 1100 a is located at fueling station 2200for refueling. When nozzle 2225 a is engaged with vehicle 1100 via fuelreceptacle 1125, dispenser 2200 a provides first nozzle information 1025corresponding to nozzle 2225 a to the first vehicle. Responsive to firstnozzle information 1025, feedback from vehicle 1100 a is provided viawireless connection 2050 a that the fueling station can use to pairnozzle 2225 a with vehicle 1100 a to initiate a fueling event.

Because RSU 2250 may have established wireless connections with multiplevehicles (e.g., vehicle 1100 b, 1100 c, etc.), the fueling station needsto resolve which vehicle has engaged with which nozzle (e.g., thefueling station needs to identity which of the vehicle that it iscommunicating with has engaged with the nozzle so that it can ascertainwhich tank parameters belong the vehicle engaged for refueling). Byproviding nozzle information and receiving feedback responsive to thenozzle information, vehicle-to-nozzle pairing can be performed withoutrequiring the vehicle to provide identification information specific tothe vehicle or the vehicle's operator. An exemplary method that allowsvehicle-to-nozzle pairing to be performed anonymously is described belowin connection with FIG. 6. It should be appreciated that a vehicle mayvoluntarily provide identification information for the vehicle orvehicle operator (e.g., to perform automatic payment), but aspects ofthe inventors' contribution allow for vehicle-to-nozzle pairing and thesubsequent fueling event to be performed anonymously without requiringsuch information.

FIG. 6 illustrates an exemplary method of performing vehicle-to-nozzlepairing, in accordance with some embodiments. Method 1600 may beperformed, for example, in the context of the system illustrated in FIG.5. Act 1610 comprises establishing a wireless connection between afueling station and a vehicle. For example, act 1610 may be performed byestablishing a first connection between an RSU positioned at the fuelingstation and a first OBU associated with a first vehicle, such as a V2Xconnection discussed above in connection with FIG. 4A. Act 1610 may beperformed to establish a wireless connection between the fueling stationand any vehicle within the zone of communication of the fueling station(e.g., fueling station may establish one or more direct connectionsand/or one or more indirect connections via vehicle hopping).Accordingly, act 1610 may be repeated to establish connections with anynumber of vehicles with a zone of communication of the fueling station.

Act 1620 comprises engaging a dispenser nozzle with a vehicle to begin arefueling process. For example, a vehicle operator or fueling stationpersonnel may attach a dispenser nozzle to a fuel receptacle of thevehicle. Because a wireless connection may be established with multiplevehicles in a zone of communication of the fueling station, the fuelingstation may not be able to ascertain which vehicle has engaged with thedispenser nozzle. For example, a fueling station may obtain tankinformation (e.g., tank size, measured tank pressure and temperature,etc.) from multiple vehicles via respective wireless connections but beunable to determine which information corresponds to the vehicle thathas engaged with the dispenser nozzle for refueling. Accordingly, thefueling station may need to resolve the correct pairing betweendispenser nozzle and vehicle to safely and correctly refuel the vehicle.At conventional fueling stations, a dispenser nozzle could only receivetank information from the vehicle to which the nozzle was engaged due tothe LOS limitations of the IrDA link over which this information istransmitted so that vehicle-to-nozzle pairing was accomplished simply byengaging the dispenser nozzle with the vehicle and establishing the IrDAlink.

Act 1630 comprises providing nozzle information corresponding to thedispenser nozzle to the vehicle engaged with the dispenser nozzle.Nozzle information may comprise information of any type (or of multipledifferent types) and may be provided in any suitable manner, such astransmitting nozzle information electronically to the vehicle (e.g., viaa low power radio frequency transmitter, such as an RFID tag),delivering nozzle information as a fluid flow signature (e.g., ahydrogen gas flow pattern), or a combination of both, as discussed infurther detail below in connection with FIGS. 7-9. According to someembodiments, at least some of the nozzle information provided in act1630 is changed or varied each time the nozzle is engaged with avehicle. In exemplary act 1630, nozzle information is provided via thedispenser nozzle so that only the vehicle engaged with the respectivedispenser nozzle receives the nozzle information so that thecorresponding vehicle-to-nozzle pairing can be correctly resolved.

Act 1640 comprises receiving feedback from the vehicle responsive to thenozzle identification information via the wireless connection. Thefeedback from the vehicle will depend on the manner in which nozzleinformation was provided to the vehicle. For example, the nozzleinformation may include a nozzle ID (e.g., a nozzle ID number) providedto the vehicle (e.g., electronically) that the vehicle parrots back tothe fueling station via the wireless connection established between thefueling station RSU and the vehicle OBU. As another example, the nozzleinformation may include a fluid flow signature delivered to the fueltank that causes changes in tank parameters (e.g., tank pressure)transmitted by the vehicle to the fueling station via the RSU/OBUwireless connection. As yet another example, nozzle information mayinclude both a nozzle ID and a fluid flow signature so that feedbackreceived from the vehicle via the wireless connection comprises both thenozzle ID and changes in transmitted tank parameters resulting fromdelivering the flow signature to the vehicle's fuel tank.

Act 1650 comprises associating the wireless connection between thefueling station and the vehicle (e.g., a V2X connection between thefueling station RSU and the vehicle OBU) with the correspondingdispenser nozzle based on the received feedback to pair the dispensernozzle with the vehicle. Thereafter, the fueling station knows thatfueling information (e.g., tank parameters) received over the wirelessconnection corresponds to the vehicle engaged with the paired nozzle andcan be used to initiate a fueling event with that vehicle via the pairednozzle (act 1660). For example, fueling information received via thewireless connection over which the feedback was received may be routedvia the fueling station's communication network to the dispenser havingthe paired nozzle so that the dispenser can control the fueling of thevehicle's tank, aspects of which are described in further detail below.

By providing nozzle information to the vehicle and receiving feedbackfrom the vehicle responsive to the nozzle information, the fuelingstation can accomplish vehicle-to-nozzle pairing without requiring thevehicle to provide vehicle identification or vehicle operatoridentification information to the fueling station. However, in somecircumstances, the vehicle may provide (or may have provided)identification information voluntarily in order to perform actions suchas automatic payment, nozzle reservation, etc. Thus, vehicle-to-nozzlepairing method 1600 allows for, but does not require, vehicle anonymity.If vehicle identification information is provided to the fuelingstation, this information may be used during vehicle-to-nozzle pairing(e.g., to confirm that a vehicle that has made a nozzle reservation isthe same vehicle engaged with the nozzle) and/or may be used during thefueling event (e.g., to perform automatic payment), as discussed infurther detail below.

According to some embodiments, a vehicle may engage with a dispensernozzle prior to establishing a wireless connection with the fueling. Insuch circumstances, the act of engaging the dispenser nozzle with thevehicle and/or the act of providing nozzle information to the vehiclemay trigger the fueling station or the vehicle to initiate establishinga wireless connection between, for example, a fueling station RSU andthe vehicle's OBU. As such, act 1610 need not be performed first, butinstead may be performed after the vehicle engages, or in response tothe vehicle engaging with a dispenser nozzle at the fueling stationand/or after or in response to nozzle information being provided by thedispenser via the nozzle to the vehicle, as the aspects are not limitedin this respect.

FIG. 7 illustrates an exemplary vehicle-to-nozzle pairing method inwhich providing nozzle information to a vehicle includes electricallyproviding a nozzle ID to the vehicle that corresponds to the nozzleengaged with the vehicle. In exemplary method 1700, acts 1610 and 1620may be the same as or similar to acts 1610 and 1620 described inconnection with FIG. 6. Act 1730 comprises providing nozzle informationto the vehicle at least in part by electrically transmitting a nozzle IDto the vehicle corresponding to the nozzle engaged with the vehicle(e.g., by performing act 1620). Electrically transmitting a nozzle IDmay be performed using any type of electrical-based communication (e.g.,electrical, electro-optical, electromagnetic, etc.) including, but notlimited to, direct electrical communication, radio frequencycommunication, optical communication and/or any suitable wired orwireless communication technique suitable for transmitting a nozzle ID.It should be appreciated that act 1730 may also include providingadditional nozzle information, either electrically or otherwise, tovehicle, as the aspects are not limited to transmitting any particularnozzle information to the vehicle.

The nozzle ID may be any type of identifier that can be used todifferentiate the nozzle from the other nozzles at the fueling stationat a given moment in time. According to some embodiments, a nozzle IDcorresponding to a given nozzle is changed each time a nozzle is engagedwith a vehicle. For example, the nozzle ID can be changed for eachnozzle by configuring the respective dispenser(s) (e.g., a dispensercontroller or other computing unit) to generate a random orpseudo-random number and assign the generated number to a nozzle thathas been engaged with a vehicle, select from a set of predeterminednozzle IDs, or perform any other suitable technique of assigning anozzle ID to each nozzle so that no two nozzles are assigned the samenozzle ID at the same time and so that the nozzle ID of a nozzle changesperiodically, after each fueling event and/or in response to some otherevent, as the aspects are not limited in this respect. According to someembodiments, nozzle IDs assigned to different nozzles are changedperiodically (e.g., hourly, daily, etc.) as an alternative, or inaddition to, changing the nozzle each time a nozzle is engaged with avehicle.

Act 1740 comprises receiving feedback from the vehicle responsive toproviding nozzle information, including receiving the nozzle ID that wasprovided to the vehicle in act 1730 as feedback via a wirelessconnection established between the vehicle and fueling station (e.g., aV2X connection established in act 1610 between the fueling station RSUand the vehicle's OBU), For example, the vehicle may parrot the nozzleID received from the nozzle (e.g., via a nozzle transmitter such as anRFID tag, Bluetooth® transmitter, IrDA transmitter, etc.) back to thefueling station via the wireless connection between the fueling stationand the vehicle. As discussed above, a wireless connection between thefueling station may be established before or after the nozzle is engagedwith the vehicle and/or before or after the nozzle ID is electricallytransmitted to the vehicle, and may be triggered by performing either ofthese acts in circumstances where a wireless connection is not alreadyestablished.

Act 1750 comprises associating the wireless connection establishedbetween the fueling station and the vehicle with the dispenser nozzleengaged with the vehicle based at least in part on receiving the nozzleID via the wireless connection. According to some embodiments, when anozzle ID is received via the wireless connection, the fueling stationmay associate the wireless connection with the dispenser nozzleidentified by or corresponding to the received nozzle ID so thatinformation received from the vehicle via the wireless connection (e.g.,fueling information such as tank parameters, fueling protocols, etc.)may be routed to the dispenser comprising the corresponding nozzle tocontrol a subsequent fueling event (e.g., a fueling event initiated inact 1660 as discussed above in connection with FIG. 6).

According to some embodiments, the fueling station distributesinformation received over each established wireless connection betweenthe fueling station and vehicles within the zone of communication toeach of the dispensers. When a nozzle ID is received via one of thewireless connections, the fueling station may indicate to the dispensercomprising the corresponding nozzle which wireless connection the nozzleID was received over so that the dispenser knows to use informationreceived via that wireless connection to control a subsequent fuelingevent via the identified nozzle. Accordingly, associating a wirelessconnection with a nozzle engaged with a vehicle may include routingfueling information received via the wireless connection to thecorresponding dispenser, or indicating to the corresponding dispenserwhich fueling information presently being distributed to the dispensershould be used to control a fueling event at the corresponding nozzle.

FIG. 8 illustrates an exemplary system configured to electronicallytransmit a nozzle ID to a vehicle to facilitate vehicle-to-nozzlepairing, in accordance with some embodiments. The system illustrated inFIG. 8 may be similar in many respects to the system illustrated in FIG.5. In this exemplary system, dispensers are configured to electronicallytransmit a nozzle ID to a vehicle engaged with the nozzle. For example,to electronically transmit a nozzle ID corresponding to the respectivenozzle to a vehicle, nozzle 2225 a′ may comprise a nozzle ID transmitter2227 a and nozzle 2225 b′ may comprise a nozzle ID transmitter 2227 bconfigured to connect, either wirelessly or via a physical “wired”connection, to a receiver located at the vehicle (e.g., ID receiver 1127located proximate the fueling receptable 1125 of vehicle 1100 a).

According to some embodiments, nozzle ID transmitters 2227 a and 2227 binclude a wireless transmitter for wirelessly transmitting a nozzle IDto a wireless receiver of a vehicle engaged with the nozzle. Inembodiments configured to communicate wirelessly, wireless nozzle IDtransmitters and receivers may communicate using any suitablecommunication technology including, but not limited to, radio frequencycommunication, optical communication, etc., provided the communicationrange is limited to prevent unintentional communication links from beingestablished between a dispenser nozzle and a vehicle to which the nozzlehas not been engaged. For example, wireless nozzle ID transmitters maycomprise a low power RFID transmitter (e.g., an RFID tag) positioned onthe nozzle so that a corresponding wireless receiver on the vehicle canreceive information from the transmitter only when the nozzle is engagedwith the fueling receptacle of the vehicle (or when the vehicle's IDreceiver is in such close proximity to ensure that only that vehicle canreceive nozzle information from the nozzle). As another example,wireless nozzle ID transmitters may comprise an IrDA transmitter thatsimilarly prevents a communication link from being established unlessand until the corresponding nozzle has been engaged with the vehicle.Thus, in the exemplary system illustrated in FIG. 7, vehicle 1100 thathas engaged with nozzle 2225 a′ via fueling receptacle 1125 is the onlyvehicle capable of receiving information 1025′, which includes thenozzle ID corresponding to nozzle 2225 a′.

According to some embodiments, nozzle ID transmitters 2227 a and 2227 binclude a physical connection for transmitting a nozzle ID to a receiverof a vehicle engaged with the nozzle via a “wired connection” using anysuitable electrical connection between the nozzle ID transmitter and thereceiver at the vehicle. For example, the dispenser nozzle may beconfigured so that when the nozzle is correctly engaged with the fuelingreceptacle so that the nozzle can dispense fuel to the vehicle's fueltank, the nozzle ID transmitter also makes a physical connection withthe receiver at the vehicle to create a wired link over whichinformation 1025′ (including the nozzle ID) may be transmitted.

According to some embodiments, each time a nozzle is engaged with avehicle the nozzle is assigned a different nozzle ID. For example,dispensers 2225 a′ and 2225 b′ may change the nozzle ID corresponding toa nozzle each time the nozzle is engaged with a different vehicle. Thenozzle ID can be changed for each nozzle by configuring dispensers(e.g., a dispenser controller or other computing unit) to generate arandom or pseudo-random number and assign the generated number to anozzle that has been engaged with a vehicle, select from a set ofpredetermined nozzle IDs, or any other suitable manner of assigning anozzle ID to each nozzle so that no two nozzles are assigned the same IDat the same time. According to some embodiments, nozzle IDs assigned todifferent nozzles are changed periodically (e.g., hourly, daily, etc.)as an alternative, or in addition to, changing the nozzle each time anozzle is engaged with a vehicle.

In response to receiving a nozzle ID, the vehicle may transmit thenozzle ID back to the fueling station via a wireless connectionestablished between the fueling station and the vehicle. For example, inthe system illustrated in FIG. 8, a nozzle ID corresponding to nozzle2225 a′ is provided to the vehicle via link 1025′ established betweentransmitter 2227 a and receiver 1127 after the nozzle was engaged withfueling receptacle 1125 of the vehicle. In response to receiving thenozzle ID, vehicle 1100 provides feedback to fueling station 2200 atleast in part by causing OBU 1150 to transmit the received nozzle ID tofueling station RSU 2250 via wireless connection 2050. It should beappreciated that other information may be provided over communicationlink 2050, including dispenser information, dispenser and/or nozzlestatus, fuel station information and/or status, etc., as the aspects arenot limited to transmitting a nozzle ID. Based on the received feedback,RSU 1250 can ascertain that communication link 2050 is the communicationlink with vehicle 1100 engaged with nozzle 2225 a′.

FIG. 9 illustrates an exemplary vehicle-to-nozzle pairing method inwhich providing nozzle information to a vehicle includes delivering afluid flow signature to the vehicle via the dispenser nozzle. Exemplarymethod 1900 includes establishing a connection between the fuelingstation (act 1610) and engaging a dispenser nozzle with the vehicle (act1620) that may be performed in the manner described above in connectionwith FIGS. 6 and 7. As discussed above, establishing a connectionbetween the fueling station may be performed before or after engaging adispenser nozzle with the vehicle. Act 1930 comprises receiving fuelinginformation, including tank parameters of the vehicle (e.g., tank size,measured tank pressure, measured tank temperature, etc.), via theestablished connection. Act 1930 may be performed any time after theconnection is established with the fueling station, either before thenozzle is engaged with the vehicle, after the nozzle is engaged with thevehicle, or both (in circumstances in which the connection isestablished prior to engaging the nozzle). According to someembodiments, the fueling station monitors the fueling informationreceived via the connection throughout the period in which the fuelingstation and vehicle remain connected via the connection established inact 1610. For example, the vehicle may continuously and/or regularly(e.g., in real-time or near real-time) transmit updated tank parametersvia the established connection so that the fueling station receivesup-to-the-instant or sufficiently current updated fueling informationfrom the vehicle and can monitor changes thereof. That is, act 1930 maybe performed repeatedly (e.g., continuously and/or regularly) throughoutthe vehicle-to-nozzle pairing process (and throughout a fueling event,as discussed in further detail below), and may also monitor tankparameters prior to vehicle engagement with a nozzle (e.g., any time orthroughout the period of time that the vehicle and the fueling stationhave an established wireless connection.

Act 1940 comprises delivering a fluid flow signature to the vehicle viathe dispenser nozzle. For example, the dispenser may control the flow ofhydrogen gas through the nozzle in a specific on/off pattern so that thefuel tank of the vehicle engaged with the nozzle experiences thedelivered fluid flow signature. The fluid flow signature may be anypattern of flow that results in one or more detectable changes in thetank parameters (e.g., a detectable change in measured tank pressure) inresponse to the fluid flow signature being delivered to the fuel tank ofthe vehicle engaged to the nozzle. According to some embodiments, thefluid flow signature delivered via a nozzle is changed each time thenozzle is engaged with a different vehicle and/or the fluid flowsignature delivered via the nozzle may be changed periodically (e.g.,hourly, daily, etc.). The specific fluid flow signature delivered via anozzle may be assigned in any manner, either statically or dynamically,so that no two nozzles deliver the same fluid flow signature at the sametime (or during a same interval of time), thus allowing the nozzle to beidentified based on the fluid flow signature delivered to the vehiclecurrently engaged with the nozzle.

Act 1950 comprises associating the connection established in act 1610with the nozzle engaged with the vehicle based at least in part on oneor more tank parameters received via the connection established in act1610. As discussed above, act 1930 may be repeated at any desiredfrequency so that the fueling station can monitor changes in one or moretank parameters over time to match those changes to the expectedresponse of the fuel tank to the fluid flow signature delivered to thevehicle in act 1640. For example, the fueling station may monitor one ormore tank parameters received via the established connection and mayassociate the connection with the nozzle that delivered a given fluidflow signature (e.g., the specific fluid flow signature delivered in act1940) when changes in the one or more tank parameters match an expectedresponse of the fuel tank to receiving the given fluid flow signature.That is, when changes in the one or more tank parameters received viathe established connection reflects the expected response to the fluidflow signature, the fueling station can ascertain which connection isassociated with the vehicle engaged at the corresponding nozzle, thusallowing or facilitating the vehicle-to-nozzle pairing to be resolved.

For example, referring again to FIG. 5, providing nozzle information1025 may include dispenser 2220 a controlling nozzle 2225 a to deliver agas flow pattern corresponding to the nozzle to fueling receptacle 1125of vehicle 1100 a. The hydrogen gas flow pattern then causes changes tothe tank parameters that are reflected in the vehicle tank data receivedby vehicle ECM 1160 and transmitted to RSU 2250 via OBU 1150 overestablished wireless connection 2050 a. Fueling station 2200 may beconfigured to monitor tank data received from each of the vehicles withwhich the fueling station has established a connection. When changes inreceived tank data from a vehicle matches expected changes resultingfrom delivering a fluid flow pattern, the fueling station associates thewireless connection over which the matched tank data was received withthe nozzle that delivered the corresponding flow pattern, therebypairing the vehicle and the nozzle.

FIG. 10 illustrates an exemplary vehicle-to-nozzle pairing method whichprovides nozzle information to a vehicle both by electricallytransmitting (e.g., via wireless optical or radio frequencytransmission) a nozzle ID and by delivering a fluid flow signature tothe vehicle via the dispenser nozzle. For example, when a vehicleengages with a nozzle (act 1620), the dispenser may electricallytransmit a nozzle ID corresponding to the nozzle to the vehicle thatuniquely identifies the nozzle (act 1730′) and may deliver a flowsignature to the vehicle to cause an identifiable change in tankparameters of the vehicle (act 1940′). As a result, feedback transmittedfrom the vehicle and received by the fueling station via a wirelessconnection established in act 1610 may include both the nozzle ID (act1740′) and tank information (act 1930′).

Act 10050 comprises associating the connection over which the feedbackwas received with the nozzle engaged with the vehicle. For example, act10050 may include any of the actions described in connection with acts1750 and 1950 of FIGS. 7 and 9, respectively, to resolve the correctvehicle-to-nozzle pairing. Basing vehicle-to-nozzle pairing on bothtypes of feedback allows the fueling station to confirm the associationand/or may enable vehicle-to-nozzle pairing when one or the othertechnique is not available. For example, some vehicles may not includethe receiver needed to receive the electrically transmitted nozzle ID,or the receiver may currently be inoperable, but vehicle-to-nozzlepairing could still be accomplished via flow signature techniques.

As discussed, the V2X communication techniques discussed above allow afueling station to establish a controller area network (CAN)communicatively connecting vehicles in-range of the fueling station'sRSU (e.g., as described in connection with the CAN illustrated in FIG.2A) and/or communicatively connecting vehicles in a larger zone ofcommunication using vehicle hopping (e.g., as described in connectionwith the CAN illustrated in FIG. 2B and vehicle hopping techniquesdescribed in connection with FIG. 3). As a result, a fueling station canreceive a rich set of information from vehicles at, near and/or at adistance from the fueling station that can be used to perform a widerange of actions at the fueling station, some examples of which arediscussed in further detail below. In the following discussion ofexemplary actions taken by the fueling station, the described actionsmay be performed by the fueling station via any one or combination ofcomponents at the fueling station including, but not limited, any one orcombination of components connected to the fueling station network suchas one or more fueling station controllers, dispenser controllers,system controllers for sub-systems of the fueling station (e.g.,controllers for hydrogen cooling systems, hydrogen gas supply systems,dispenser island systems, etc.), or any other suitable component orcombination of components.

According to some embodiments, based on information received fromvehicles in the CAN, the fueling station can predict the near-termdemand on the fueling station from the number of vehicles needingrefueling and can configure the fueling station to meet those demandsand/or to reduce energy consumption when the information indicates theability to do so. FIG. 4B illustrates an exemplary method performed inresponse to receiving fueling information via a CAN comprising aroad-side unit at a fueling station and a plurality of on-board unitsassociated with respective vehicles with which the road-side unit hasestablished respective wireless connections (e.g., by performing acts1410 and 1420 as discussed above in connection with FIG. 4A). Thefueling information received by performing act 1420 may include anyinformation or combination of information from the vehicle thatfacilitates determining an expected demand at the fueling stationincluding, but not limited to one or more tank parameters that allow thefueling station (e.g., via one or more controllers coupled to road-sideunit) to determine how much fuel a vehicle presently has, location ofthe vehicle to determine how far the vehicle is from the fuelingstation, whether a vehicle is moving towards or away from the fuelingstation, proximity of a vehicle to another fueling station, etc.).

In the embodiment illustrated in FIG. 4B, this received fuelinginformation is used by the fueling station (e.g., via the one or morecontrollers) to estimate the expected refueling demand at the fuelingstation so that the fueling station can prepare the fueling station tomeet the expected demand (act 1432). In act 1434, the expected demanddetermined from the received fueling is used to power up one or morecomponents of the fueling station (e.g., to meet an expected increase indemand) or power down one or more components of the fueling station inview of an expected decrease in demand. For example, if the fuelinginformation obtained from the CAN indicates that the fueling station islikely to experience of period of little or no demand, the fuelingstation may respond by powering down one or more components of thefueling station. As another example, the fueling station may be in areduced power consumption state (e.g., one or more components of thefueling station may have been powered down to reduce power consumption)and in response to information received via the CAN indicatingrelatively near-term demand, the fueling station may power up one ormore components of the fueling station to ensure that the fuelingstation is able to meet the demand.

According to some embodiments, the fueling station may respond toinformation received via the CAN to disable operation of one or morerefrigeration units (e.g., power down one or more refrigeration units orone or more components of a refrigeration unit), associated pumps, etc.of a hydrogen cooling system to reduce power consumption at the fuelingstation when information received via the CAN indicates a level ofdemand that allows the fueling station to operate in a reduced powerstate. For example, disabling operation of a refrigeration unit maycomprise powering down or turning off one or more components of therefrigeration unit to save on power that would otherwise be consumed toreduce and/or maintain the temperature of coolant used by a hydrogencooling system to chill hydrogen gas. Disabling operation of a component(e.g., a refrigeration unit, dispenser, pump, motor, etc.) may involvepowering down or turning off some portions of the component whilekeeping some portions of the component powered up.

According to some embodiments, the fueling station responds toinformation received via the CAN to enable operation of one or morerefrigeration units (e.g., power up one or more refrigeration units orone or more components of a refrigeration unit), associated pumps, etc.of a hydrogen cooling system when information received via the CANindicates the need to do so to meet the likely near-term refuelingdemands on the fueling station. For example, enabling operation of arefrigeration unit may comprise powering up or turning on one or morecomponents of the refrigeration unit that were previously disabled toresume reducing and/or maintaining the temperature of coolant used by ahydrogen cooling system to chill hydrogen gas. Enabling operation of acomponent (e.g., a refrigeration unit, dispenser, pump, motor, etc.)refers generally to powering up or turning on portions of the componentneeded to operate and/or resume operation. Further examples of usinginformation received via the CAN to reduce power consumption, optimizeperformance and/or otherwise configure components of the fueling stationare discussed in further detail in connection with the exemplaryhydrogen cooling systems described below.

According to some embodiments, the fueling station may respond toinformation received from the CAN to provide information to vehicleswith which the fueling station has established a connection such asstatus information on the fueling station or status information ofanother fueling station, fuel availability, estimated wait times, theavailability of fuel at different temperature classes, estimated waittimes, navigation information to the fueling station or other fuelingstations, etc. (e.g., when performing act 1420 in the exemplary methodsillustrated in FIGS. 4A-C). In this manner, status information may bebroadcast to all vehicles to which a fueling station is connected and/orinformation specific to a given vehicles may be transmitted over therespective wireless connection so that different information istransmitted to different vehicles based on the specific informationprovided by the corresponding vehicle over its established connection.

Any combination of the above information may be transmitted from thefueling station RSU to OBUs of vehicles having established connectionswith the RSU, and the vehicles' ECM can display this information to thevehicle operator and/or recommend that the operator of the vehicle driveto the fueling station when the conditions at the fueling station arefavorable and/or suitable or recommend that the operator of the vehiclecontinue to a different fueling station where conditions may be morefavorable and/or suitable. In embodiments in which navigationinformation to one or more fueling stations is provided, this navigationinformation can be used to guide the operator of the vehicle to thefueling station that can best meet the current needs of the vehicle. Inthis way, helpful fueling information may be provided to vehicles toassist in refueling vehicles and/or current fueling demands of vehiclesin a zone of communication can be distributed across multiple fuelingstations to optimally meet that demand.

According to some embodiments, the fueling station may respond toinformation received from the CAN to perform nozzle reservation for avehicle so that the vehicle can be assured of having an available nozzleat which to refuel when the vehicle arrives at a fueling station (e.g.,at a specified reservation time, within a specified reservation window,any time after a specified earliest reservation time, etc.). FIG. 4Cillustrates an exemplary method performed in response to receiving anozzle reservation request via a CAN comprising an RSU at a fuelingstation and one or more OBUs associated with a respective vehicle(s)with which the road-side unit has established a wireless connection(e.g., by performing acts 1410 and 1420 as discussed above in connectionwith FIG. 4A), in accordance with some embodiments.

In the exemplary nozzle reservation method illustrated in FIG. 4C, forexample, the RSU at a fueling station receives a request via the OBU ofa vehicle to reserve a nozzle for a refueling event (act 1424) duringdata exchange with the OBU (act 1420). The request may include theamount of fuel needed, the required or preferred temperature class ofthe fill, a time or time periods for the reservation, or the fuelingstation may determine the parameters of the request from otherinformation received from the vehicle (e.g., tank volume and currenttank pressure, tank temperature, location of the vehicle if provided,etc.). In act 1426, the fueling station (e.g., via one or morecontrollers coupled to the RSU) negotiates the reservation with thevehicle.

Negotiating the reservation may include any processing needed to confirma nozzle reservation for the requested reservation and may include bothdata exchange (e.g., act 1426 as part of data exchange 1420) andperforming action at the fueling station (e.g., act 1426 as part of act1430). For example, negotiating the reservation may include one or anycombination of determining whether there is one or more dispensers atthe fueling station that are capable of fulfilling the reservation orcan be made ready to fulfill the reservation, further data exchange withthe OBU to obtain additional information, modifying one or moreparameters of the requested reservation, proposing one or moreparameters for the requested reservation, providing a reservationidentifier, confirming the reservation, etc. Once the nozzle reservationhas been negotiated, one or more actions may be performed at the fuelingstation to prepare for fulfilling of the reservation (act 1436)including, but not limited to, associating information with thereservation, informing one or more dispensers of the reservation,powering up one or more components of the fueling station to make surethat the requested fueling event can be performed when the vehiclearrives for its reservation, etc., examples of which are described infurther detail below. When the vehicle with the reservation arrives atthe fueling station, the fueling station fulfills the reservation (act1438) by performing a fueling event via a reserved dispenser.

A fueling station may prepare for a reservation (e.g., may perform act1436) in any number of suitable ways. For example, if multiple dispensernozzles are ready and available (or can be made to be ready andavailable prior to the reservation time) to perform the reserved fuelingevent, each available dispenser may be informed of the reservation. Inthis way, any of the available dispensers may still be used to performintervening fueling events so long as at least one dispenser remainsready to fulfill the reservation. As such, vehicles that may arrive atthe fueling station prior to the reservation need not be inconveniencedby inadvertently pulling up to a specific dispenser that has beentemporarily dedicated to fulfilling a reservation and instead canutilize the dispenser unless and until only one dispenser nozzle remainsthat can fulfill the reservation. The dispenser numbers, for example, ofdispensers that can fulfill the reservation may be conveyed to thevehicle with the reservation so that the vehicle can refuel at any ofthose dispensers. Dispenser availability can be updated (e.g., byperforming further data exchange 1420) as needed prior to thereservation in the event that intervening vehicles utilizing one or moredispensers to refuel cause that dispenser to be unavailable to fulfillthe reservation. According to some embodiments, a single dispenser (or asingle nozzle of a multi-nozzle dispenser) is assigned to fulfill areservation and therefore may be unavailable to other vehicles duringsome prescribed time unless the dispenser is capable of performing oneor more refueling events and still be able to fulfill the reservation.

According to some embodiments, the reservation request received by thefueling station via the established connection (e.g., act 1424) mayinclude identification information associated with the vehicle or thevehicle's operator and this identification information may then beassociated with the reservation (e.g., during act 1426 or 1436). Thatsame identification information may then be conveyed to the fuelingstation during vehicle-to-nozzle pairing using any of the techniquesdescribed in the foregoing to confirm that the vehicle engaged at anozzle has reserved the nozzle (e.g., when a single nozzle is assignedto fulfill the reservation) and/or to indicate that the subsequentrefueling event fulfills that reservation (e.g., when any availabledispenser can be used to fulfill the reservation).

According to some embodiments, nozzle reservation may be performedanonymously. For example, when a vehicle requests a nozzle reservationand the fueling station confirms the reservation (e.g., by performingacts 1424 and 1426), the fueling station may associate the establishedconnection with the vehicle to that reservation (e.g., by assigning aunique reservation number to the established connection). Thus, when thefueling station associates that established connection with a givennozzle during vehicle-to-nozzle pairing using any of the techniquesdescribe above, the fueling station can confirm that this connectionalso has the reservation associated with it. Anonymous nozzlereservation can therefore be performed both when a single dispenser isdedicated to the reservation or when any available dispenser can be usedto fulfill the reservation. According to some embodiments using theabove technique for anonymous nozzle reservation, the same connectionwith the fueling station over which the reservation request was made mayneed to be maintained through to the completion of the refueling event.However, according to some embodiments, when a reservation is made, thefueling station may assign a unique number to that reservation (e.g., apseudo-random number of sufficient length that ensures the reservationcannot be spoofed) and convey that reservation number to the vehicle(e.g., during reservation negotiation 1426). Should the establishedconnection be disconnected (either inadvertently or intentionally in act1440), the vehicle may convey the unique reservation number to thefueling station when a connection between the vehicle and the fuelingstation is established prior to a fueling event (e.g., during act 1610of refueling event 1600 illustrated in FIG. 6) so that the connectionestablished for the refueling event need not be the same connection overwhich the reservation was made.

According to some embodiments, a V2X connection with a vehicle and afueling station is used to exchange payment information to allowautomatic payment for a fueling event. For example, the vehicle mayprovide debit or credit card information or other information needed toperform any type of electronic payment to the fueling station over theestablished connection (e.g., via data exchange 1420) to facilitatesecure transmission of payment information that allows the fuelingsystem to process payment for a fueling event without needing thevehicle operator to interact with the dispenser (e.g., by inserting adebit or credit card into the dispenser) and/or fueling stationpersonnel to pay for the fueling event, facilitating simpler and moreconvenient transactions and/or more efficient fueling events.

According to some embodiments, a fueling station uses informationreceived from vehicles via the CAN to optimize a fueling event forindividual vehicles. As discussed above, the increased bandwidth of V2Xcommunications allows for a richer set of information about a vehicle tobe transmitted to the fueling station (e.g., via data exchange 1420).For example, in addition to the limited set of tank parameters (e.g.,tank pressure, tank temperature, tank size, etc.) transmitted viaconventional LOS communications established between the vehicle and thedispenser via the nozzle, information about the specific fuelingpreferences, requirements and/or capabilities may be transmitted to thefueling station so that the dispenser can optimize a fill according tothe preferences, requirements and/or capabilities of a specific vehicleconveyed to the fueling station via an established V2X connection. As aresult, a dispenser may be configured to deliver a faster fill wheninformation received from the vehicle confirms that the dispenser can doso safely.

According to some embodiments, a fueling protocol for the vehicle may betransmitted to the fueling station via the established V2X communicationthat can be used by the dispenser to optimize a fueling event for thevehicle. The fueling protocol may include, among other information,target tank pressure as a function of time that the dispenser shouldfollow when performing a fueling event. This pressure profile can beused by the dispenser controller to vary the flow rate of hydrogendelivered to the fuel tank of a vehicle to follow the pressure profilespecified by the fueling protocol. In this way, a dispenser can beconfigured to refuel a vehicle in accordance with the fueling protocolspecified by the vehicle, further details of which are discussed inconnection with the exemplary dispenser controllers described below.

According to some embodiments, information received by a fueling stationvia a CAN (e.g., via data exchange 1420) may be used to develop trenddata on demand (e.g., time of day of peak demand, average demand for thefueling station, weekday vs. weekend demand, predominant type of vehiclebeing refueled during different times, etc.) that can be used tooptimize the fueling station. For example, trend data can be used tocreate daily demand schedules that can be used by the fueling station toguide in the powering up or powering down one or more components of thefueling station. This information may be used to supplement and/orconfirm current demand information received via the CAN. For example,the fueling station may determine from information received via the CANthat there may be little or no near-term demand but may decide to keepone or more components powered-up based the proximity in time to peakdemand time captured by the trend data. Trend data may be used inmultiple other ways such as determining an optimal configuration ofcomponents (e.g., hydrogen cooling system configuration), schedulingdelivery of hydrogen gas, to guide in optimally configuring a newfueling station deployment or in other ways, as the aspects are notlimited in this respect.

As discussed above, many current fueling protocols adopted by hydrogenrefueling stations require hydrogen fuel to be cooled between −40° C. to−17.5° C. prior to dispensing to the vehicle to ensure the vehicle'sfuel tank maintains bulk gas temperatures below 85° C. regardless ofambient temperatures or previous driving conditions. As discussed above,existing hydrogen gas fueling stations typically employ either a largechilled aluminum block that provides a thermal reservoir to coolhydrogen gas prior to dispensing or a diffusion-bonded heat exchangerthat cools hydrogen gas by circulating chilled coolant through aplate-to-plate configuration. The inventors have recognized that whileeach technique has some advantages, both have significant drawbacks.Aluminum block heat exchanger systems are massive (e.g., 600-1000 kg)and costly (e.g., $100-150K per installation), and typically requirebreaking ground to bury the aluminum block beneath the dispenser, whichmay limit the locations for these installations and increases the cost.Additionally, contact resistance between the aluminum block and thestainless-steel tubing causes heat transfer inefficiency resulting in alow UA (overall heat transfer coefficient, U, multiplied by the heattransfer area, A) heat exchanger. Thus, aluminum block heat exchangershave relatively long fueling times (e.g., 5 minutes). Aluminum blockheat exchangers generally are employed on a per dispenser basis so thatmultiple installations are required for fueling stations having multipledispensers, making the aluminum block heat exchanger solution difficultand costly to scale. One advantage of aluminum block heat exchangers isthat once cooled, the large thermal mass of the aluminum block allowsthe low temperature of the aluminum block to be maintained withrelatively low energy output (e.g., 19 kW) so that relatively smallcapacity refrigeration units can be used maintain the target temperatureof the aluminum block.

Conventional high UA heat exchanger systems (e.g., cooling systems thatemploy diffusion-bonded plate-to-plate heat exchangers) are typicallyeven costlier (e.g., $200K per installation), but these systems providefor a high UA heat exchange allowing for faster fill times (e.g., on theorder 2 minutes for some installations). Conventional diffusion-bondedheat exchanger systems employ relatively low volume coolant reservoirs(e.g., between 20-50 gallons) and large-capacity refrigeration unit(e.g., 35-70 kW capacity chillers) are required to maintain the lowtemperature of this low thermal mass coolant reservoir to meet peakfueling demands. Use of large-capacity chillers has a number ofdrawbacks. In particular, large-capacity chillers are themselvesexpensive and consume significant power and to the cost of operatingthese refrigeration units. Also, the large size of these chillers oftenprevents installation of the chiller proximate the dispenser. As aresult, the coolant reservoir and chiller are typically installed somedistance from the dispenser and must be connected to the heat exchangerat the dispenser with lengths of tubing.

The inventors have designed and developed high UA hydrogen coolingsystems that address one or more of the above drawbacks associated withconventional hydrogen cooling systems. For example, the inventors haveappreciated that the conventional approach of using a small-volumecoolant reservoir and large-capacity refrigeration unit (chiller)results in both large and costly hydrogen cooling systems. The inventorsrecognized that by increasing the volume of the coolant reservoir, thethermal energy capacity of the reservoir can be increased, thus takingadvantage of the high thermal mass characteristics of aluminum blockheat exchangers without incurring the heat transfer inefficiency andother drawbacks of that solution. According to some embodiments, a heatexchanger system comprises a coolant reservoir of between 50-700 gallons(e.g., a 100-gallon tank of a coolant such as glycol) to increase thethermal energy storage capacity of the reservoir. As used herein, alarge-volume reservoir refers to reservoir with an equal to or greaterthan 50 gallon holding capacity (in some embodiments, preferably greaterthan 80 gallons, and in some embodiments, preferably 100 gallons orlarger).

The inventors further recognized that the increased thermal storagecapacity of the large volume reservoir allows for the use of asignificantly smaller refrigeration unit. Specifically, becauseincreasing the volume of the reservoir increases the thermal energycapacity, the volume of the reservoir can be sized to handle peak demandso that the refrigeration unit need only be sized to handle the baseload refueling needs of the fueling station. According to someembodiments, a small-capacity refrigeration unit is used to cool a largevolume coolant reservoir, both sized according to the needs of thefueling system. As used herein, a small-capacity refrigeration unit(chiller) refers to a refrigeration unit have a capacity of greater than3 kW and less than or equal to approximately 21 kW. The capacity of arefrigeration unit is often stated in terms of tons where each tonprovides an additional 3.517 kW capacity approximately. Thus, asmall-capacity refrigeration unit refers to between, and including,between approximately 1-ton and 6-ton refrigeration units.

Furthermore, the inventors have appreciated that aspects of this designfor hydrogen cooling (e.g., large volume reservoirs and small chillersrelative to conventional approaches) provides a flexible design approachthat can be optimized according to the performance needs of a particularfueling station. For example, a fueling station requiring higherperformance may size-up the capacity of the refrigeration unit to reducerecovery times and/or increase the volume of the coolant reservoir toincrease the peak capacity of the station (e.g., the number ofback-to-back fills that can be performed). Fueling stations requiringless demanding recovery times and/or that need less peak capacitycapabilities can be sized down accordingly to provide a lower costsolution that meets the performance requirements of the fueling station,as discussed in further detail below.

The inventors have further appreciated that aspects of theabove-described combination of components facilitate compact designsthat allow for compact hydrogen cooling system that can be installedproximate the dispenser (e.g., next to or adjacent to one or moredispensers) delivering chilled hydrogen into fuel tanks of HFCVs.Additionally, using a large-volume reservoir/small-capacityrefrigeration/high UA heat exchanger combination provides a flexiblearrangement that can configured in different ways and optimized for aparticular fueling station, providing a highly flexible, scalable andcost-effective solution to hydrogen cooling.

According to some embodiments, the hydrogen cooling system according tothese techniques is provided in which a large-volume coolant reservoir,small-capacity refrigeration unit and heat exchanger are integrated anddeployed as a single compact unit (e.g., integrated within the samehousing). According to some embodiments, this integrated hydrogencooling unit is located proximate the dispenser(s) (e.g., adjacent toone or more dispensers, or located on the canopy over the dispensers)for which the unit provides cooling. According to some embodiments, asingle hydrogen cooling system provides cooling for a plurality ofdispensers. For example, a fueling station may comprise one or moreislands, each island having multiple dispensers (e.g., multiple nozzlesby which a respective multiple number of vehicles can be simultaneouslyrefueled). The multiple dispensers on each island may share a singlehydrogen cooling system, which cooling system may be an integrated unitor may be of a different design, as the aspects are not limited in thisrespect. According to some embodiments, a single small-capacityrefrigeration unit may be coupled to a single large-volume reservoir ormultiple large-volume reservoirs. Using either configuration, eachlarge-volume reservoir may provide coolant for one or multipleexchangers that are in turn coupled to one or multiple dispensers. Anumber of exemplary configurations are illustrated and described infurther detail below.

The inventors have further appreciated that the thermal energy capacityof a hydrogen cooling system may be increased by using phase changematerial (PCM) that stores latent heat energy during transition from onestate to another (e.g., energy is stored by the phase change materialduring a change from a liquid to a solid as a result of cooling thephase change material) to increase the heat energy capacity of thereservoir. The latent heat energy stored by the PCM is released as thePCM changes state when absorbing heat from a hydrogen gas to cool thehydrogen for dispensing to the fuel tank of a vehicle. That is, heatremoved from hydrogen gas (or heat removed from conventional coolantthat has absorbed heat from hydrogen gas) results in state change of thePCM rather than heating of the PCM (or conventional coolant) and thusprovides a thermal buffer for the hydrogen cooling system. As a result,the increased heat energy capacity resulting from PCM techniques can beused to increase the back-to-back fill capacity of the hydrogen coolingsystem and/or to decrease the size and expense of the refrigeration unitneeded to meet the fueling requirements of a specific refueling station.The inventors have recognized that a class of PCMs known as eutecticscharacterized by having a low temperature phase change are well suitedfor hydrogen gas cooling applications, however, other PCMs may be usedin some embodiments, as discussed in further detail below.

It will be understood that all materials change state at sometemperature and are therefore strictly speaking phase change materials.However, as used herein, a phase change material refers to a coolantthat has a phase change temperature in the range of intendedtemperatures of the hydrogen cooling system and that exists in a firststate at ambient temperatures and is caused to transition to a secondstate when chilled by components of a hydrogen cooling system to storeheat energy via the state transition. Similarly, a non-PCM coolant(e.g., glycol) is a material that has a phase change temperature outsidethe range of intended temperatures of the hydrogen cooling system andthat exists in a first state at ambient temperatures and remains in thatfirst state when chilled by components of the hydrogen cooling system.

According to some embodiments, the above-described hydrogen coolingsystems can employ conventional plate-to-plate diffusion bonded heatexchangers. However, diffusion-bonded heat exchangers are by themselvesexpensive, costing anywhere from $40-100K, thus potentially limiting thescalability and/or flexibility of these solutions. To facilitate furtherreduction in the cost of a hydrogen cooling system, the inventors havedeveloped a high UA annular heat exchanger designed for high pressureheat exchange that, according to some embodiments, can be used in placeof expensive diffusion-bonded heat exchangers, thereby further loweringthe cost of the hydrogen cooling system and improving the scalabilityand flexibility of the solution, facilitating further optimizationcapabilities in the design, configuration and deployment of the hydrogencooling system. As used herein, an annular heat exchanger refers to aheat exchanger in which the tubing through which hydrogen gas is formedinto an annular coil, examples of which are described in further detailbelow.

According to some embodiments, the tubing of the coil of an annular heatexchanger is made from a material (e.g., a nickel alloy) that iscompatible with hydrogen and that can withstand the pressure conditionsof a hydrogen fueling environment and is designed to have a thin wallthickness to increase heat transfer efficiency of the coil. According tosome embodiments, the annular coil is finned (e.g., copper fins) toincrease the surface area of the coil to increase heat transferefficiency. According to some embodiments, the annular heat exchanger isof a shell-and-tube configuration comprising an outer shell (e.g., acylindrical shell) through which coolant is pumped and the coil oftubing is positioned within the outer shell so that hydrogen gas flowingthrough the coil transfers heat to the coolant flowing through the outershell. According to some embodiments, an annular heat exchangercomprises a plurality of coils to increase the heat transfer capacity ofthe heat exchanger.

Following below are further detailed descriptions of various conceptsrelated to, and embodiments of, hydrogen cooling systems for refuelingof hydrogen fuel cell vehicles. It should be appreciated that theembodiments described herein may be implemented in any of numerous ways.Examples of specific implementations are provided below for illustrativepurposes only. It should be appreciated that the embodiments and thefeatures/capabilities provided may be used individually, all together,or in any combination of two or more features/capability, as aspects ofthe systems and techniques described herein are not limited in thisrespect.

FIG. 11 illustrates a block diagram of a hydrogen cooling system, inaccordance with some embodiments. The block diagram in FIG. 11 is notdrawn to scale and is meant to illustrate how components of an exemplaryhydrogen cooling system 110 are coupled to each other and to componentsof a fueling station in some embodiments. Hydrogen cooling systemcomprises refrigeration unit 112 coupled to reservoir 114 of coolant andconfigured to bring the coolant down to low temperatures (e.g., in arange from −40° C. to −17.5° C.) to facilitate fast and safe fueling ofHFCVs. As discussed above, such refrigeration units are also referred toas chillers or coolers and, unless otherwise specified, refrigerationunit, condenser unit, chiller and cooler will be used interchangeably torefer to this component configured to chill coolant that is in turn usedby heat exchanger 116 to chill hydrogen gas for dispensing into the fueltank of an HFCV. It should be appreciated that refrigeration unit may beany type of cooling source ranging from using HFC's, CO₂, glycol chillersystems or cryogenic gas, cascaded refrigeration units, etc.

Heat exchanger 116 may be any component with sufficiently high heattransfer efficiency to meet the performance requirements of a fuelingstation. According to some embodiments, an annular heat exchangerdesigned for high heat transfer efficiency and to operate under thehigh-pressure conditions of hydrogen gas refueling is used to implementheat exchanger 116, examples of which are described in further detailbelow. According to some embodiments, a conventional plate-to-plate heatexchanger, for example, a diffusion-bonded heat exchanger designed forthe high pressures of hydrogen gas refueling may be used to implementheat exchanger 116. Use of an annular heat exchanger may be preferablefor many fueling stations due to its lower cost, size and/or flexibility(e.g., the suitability of an annular heat exchanger to be used inconjunction with embodiments employing PCMs), but aspects are notlimited in this respect.

During a refueling event, chilled coolant from reservoir 114 andhydrogen gas from hydrogen source 122 are pumped through heat exchanger116 (e.g., via pumps 115) where the chilled coolant absorbs heat fromthe hydrogen gas as the coolant and hydrogen gas pass through the heatexchanger. Hydrogen source 122 refers to any source from which heatexchanger receives hydrogen. For example, hydrogen source 1122 may be abank of hydrogen storage tanks at the fueling station. According to someembodiments, hydrogen source 122 may be the dispenser in configurationswhere the hydrogen cooling system is coupled downstream of the dispenserflow control valve, examples of which are described in further detailbelow. The chilled hydrogen gas may then be provided to dispenser(s) 120for delivery during to the fuel tank of an HFCV during a fueling event.The coolant is recirculated back to the reservoir. Refrigeration unit112 is operated to maintain the desired temperature of the reservoirand/or to recover the temperature of the reservoir coolant to thedesired temperature as one or more refueling events increases thetemperature of the reservoir coolant. For example, coolant many becirculated between refrigeration unit 112 and reservoir 114 to maintainor recover the desired temperature, a refrigeration coil may bepositioned within the reservoir to maintain/recover the temperature,etc. Any of the techniques described below in connection with FIG. 12may be used to maintain and/or recover a target temperature of coolantin coolant reservoir 114.

FIG. 17 illustrates a hydrogen cooling system comprising a chillersystem having a refrigeration unit and a coolant reservoir integrated inthe same housing, in accordance with some embodiments. In the embodimentillustrated in FIG. 17, hydrogen cooling system 1700 comprises chillersystem 1712 having a refrigeration unit 1711 and a coolant reservoir1714 integrated in the same housing 1709. Refrigeration unit 1711 mayinclude an evaporator and a condenser having one or more cascaded stagescoupled to chill coolant held in the reservoir tank. It should beappreciated that refrigeration unit 1711 is exemplary and any suitablerefrigeration unit capable of chilling coolant to target temperaturesmay be used, as the aspects are not limited in this respect. Chillersystem 1712 may be coupled to one or more heat exchangers 1716 toprovide chilled coolant via supply line(s) that can be circulatedthrough the heat exchanger(s) to absorb heat from hydrogen gas fromhydrogen gas source 1705 flowing through the heat exchanger(s) 1716 toprovide chilled hydrogen gas to one or more dispensers 1720 of a fuelingstation. Coolant that has absorbed heat from hydrogen gas flowingthrough the heat exchanger(s) may then be returned to coolant reservoir1714 and refrigeration unit 1711 can be operated to recover thetemperature of the coolant reservoir, for example, using any of thetechniques described below in connection with FIG. 12 for maintainingand/or recovering a target temperature of coolant in coolant reservoir1714. According to some embodiments, one or more heat exchangers 1716may also be integrated in housing 1709 to provide a single compacthydrogen cooling unit that can be, for example, installed on a dispenserisland to provide hydrogen cooling for one or more dispensers on theisland (e.g., between a pair of dispensers deployed at the dispenserisland that share the hydrogen cooling system), some examples of whichare described in further detail below. According to some embodiments,the hydrogen cooling system is coupled downstream of the flow controlvalve of the sensor so that hydrogen gas from hydrogen gas source 1705is provided to dispenser 1720 and after flowing through the dispenserflow control valve is provided to heat exchanger 1716 and cooledhydrogen is provided to the dispenser nozzle for dispensing. Thishydrogen gas flow path is illustrated by dotted lines.

As discussed above, conventional high UA hydrogen cooling systems areimplemented using small-volume reservoirs (e.g., less than 50 gallons)and large-capacity refrigeration units (e.g., greater than 35 kWcapacity chillers), resulting in large, expensive, high power solutions.The inventors have recognized advantages in deploying large-volumereservoirs and small-capacity refrigeration units to facilitate morecompact, less expensive and/or lower power hydrogen cooling systems toprovide highly flexible and scalable hydrogen cooling solutions suitablefor a wide range of fueling stations and HFCV refueling (e.g., light,medium and heavy duty). A large-volume reservoir acts a thermal bufferand facilitates the use of smaller refrigeration units. The combinationof a large-volume reservoir and small-capacity refrigeration unit allowsfor sizing of the cooling system to meet the performance needs of aparticular fueling station. Hydrogen cooling systems comprisinglarge-volume reservoirs (i.e., greater than 50 gallons, such as between80-120 gallons for many systems, or even larger volume reservoirs suchas between 500 and 700 gallons for some medium and heavy dutyapplications) and small-capacity refrigeration units (i.e., less than orequal to 21 kW, many configurations of which may employ 10 kW capacityrefrigeration units or less) can be optimized for a range of fuelingstation needs, including industrial (e.g., fork lifts, off-roadvehicles, etc.), light duty (e.g., passenger vehicles, etc.),medium-duty and heavy-duty (busses, cargo vans, semi-trucks, etc.)applications with fueling pressures of 0 to 87.5 MPa and fuel deliverytemperatures ranging from −20-40° C., examples of which are discussed infurther detail below.

FIG. 12 illustrates an exemplary process for maintaining and/orrecovering a target temperature of coolant in a hydrogen cooling systemconfigured for hydrogen gas refueling, in accordance with someembodiments. As discussed above, a large-volume reservoir may be used tostore coolant that is chilled to low temperatures to store thermalenergy for use in cooling hydrogen gas for dispensing into HFCVs. Thetemperature of the bulk coolant in the reservoir is maintained andrecovered using a small-capacity refrigeration unit that may be operatedaccording to the exemplary process 200. In act 210, the hydrogen coolingsystem checks to see whether the temperature of the coolant is less thanor equal to a target temperature at which the reservoir is to bemaintained. Because the reservoir will lose some amount of heat even inthe absence of a fill event, the hydrogen cooling system may beconfigured to check the temperature and operate the refrigeration unit(act 215) in the event that the coolant temperature has increased abovesome threshold temperature above the target temperature. The thresholdtemperature may be chosen appropriately to avoid excessive cycles ofrunning the refrigeration unit throughout the day. Additionally, thethreshold temperature may be a variable threshold that changes dependingon information from the fueling station such as time of day, currentdemand, predicted demand, etc. This information may be provided by thefueling station, for example, based on information received via thevehicle communication techniques described in the foregoing.

Operating the refrigeration unit may include one or more tasks such asturning the refrigeration unit on, turning on pumps that circulatecoolant through the refrigeration unit, circulating coolant throughrefrigeration coils, or other acts needed to engage the process ofcooling the bulk coolant that may depend on the type of refrigerationunit and the type of coolant (e.g., direct refrigeration, circulation ofa coolant, use of refrigeration coils, use of cryogenic gas, etc.).Operation of the chiller may continue until the bulk coolant temperaturein the reservoir is sufficiently lowered (e.g., until the temperaturereaches a desired target temperature). According to some embodiments,acts 210 and 215 are performed periodically in accordance with a coolingschedule based on one or more factors, based on information from thefueling station (e.g., received via vehicle communication techniques),etc.

In addition to maintenance, the chiller may also be used to recover thetemperature of the bulk coolant in the reservoir after a fill event. Inparticular, detection of the initiation of a fueling event (e.g., when adispenser nozzle is removed from its holder and/or engaged with avehicle) in act 220 may result in operating the chiller (e.g., act 215as discussed above) and operating the heat exchanger (act 230) to cooldown the hydrogen gas before dispensing into the fuel tank of thevehicle. Operating the heat exchanger may include turning on pumps orother components needed to circulate coolant and pass hydrogen gasthrough the heat exchanger so that the coolant can absorb heat from thehydrogen gas. In act 240, chilled hydrogen gas is dispensed into thevehicle according a fueling protocol determined by communication betweenthe dispenser and the vehicle using any of the techniques describedherein. In exemplary process 200, both the refrigeration unit and theheat exchanger are operated. However, in some embodiments, therefrigeration may not be operated during or throughout a fueling eventand may instead be operated after the refueling event or according to apredetermined schedule based on, for example, historic data regardingpeak and low demand hours, the number of vehicles in the area that mayneed refueling, whether the refrigeration unit is being used to chill adifferent reservoir of coolant, energy costs at different times of theday and/or based on any other relevant information available to therefueling station.

After the refueling event is completed, operation of the heat exchangermay stop (e.g., pumps and/or other components may be turned off orpowered down) but the refrigeration may remain operational to recoverthe target temperature of the bulk coolant in the reservoir (e.g., acts210 and 215 may performed until the target temperature of the bulkcoolant is recovered). As discussed above, according to someembodiments, the refrigeration may not be operated during the fuelingevent, but instead may be operated after the refueling event (orswitched over from a different reservoir) and/or according to a coolingschedule that takes into consideration one or more factors discussedabove to optimize operation of the fueling station.

It should be appreciated that the performance characteristics of process200 (or any of the alternatives discussed above) will depend on thevolume of the reservoir (e.g., the amount of heat energy the reservoircan store) and the capacity of the refrigeration unit. As discussedabove, the capacity of a refrigeration unit refers to the coolingcapacity (heat rejection) of the chiller and is typically measured inkilowatts, but is also frequently indicated by tonnage. Typicalrefrigeration units will have approximately 3.517 kW of cooling capacity(heat rejection) per ton (e.g., a 2-ton chiller would have a coolingcapacity of approximately 7 kW, a 3-ton chiller would have a coolingcapacity of 10.6 kW, a 5-ton chiller would have a cooling capacity ofapproximately 17.6 kW, etc.).

FIG. 13 is a plot of recovery times as a function of refrigeration unit(chiller) capacity at three different ambient temperatures using a100-gallon tank as the coolant reservoir, which is this example holds aglycol coolant. As illustrated, by increasing the capacity of thechiller, recovery times can be reduced. The flexibility of this approachfacilitates a cost-benefit analysis allowing higher performance fuelingstations to be deployed at higher costs as well as lower costinstallments where higher performance may not be needed. As discussed inconnection with process 200 illustrated in FIG. 2, the chiller may beoperated during a refueling event. In such embodiments, the bulktemperature of the reservoir undergoes recovery during the refuelingevent itself. For example, a 3-ton chiller for chilling hydrogen at 25°C. ambient temperature has a recovery time of just over 5 minutes. If,for example, the chiller is operated during a refueling event that takes3 minutes to complete, the temperature of the bulk coolant may requireonly an additional 2 minutes of recovery time. It should be furtherappreciated that the bulk coolant temperature in the reservoir need notbe fully recovered to the lowest target temperature before performing asubsequent refueling event. For example, for a 7 kW refrigeration unit,a first refueling event may deliver hydrogen gas at −40° C., a secondback-to-back refueling event may deliver hydrogen gas at −30° C., and athird back-to-back refueling event may deliver hydrogen gas at −20° C.,etc. As a result, multiple back-to-back fills can be performed before adispenser will need to be temporarily taken offline to allow thetemperature of the coolant to recover. The number of back-to-back fillsthat can be performed will depend on the volume of the reservoir, thecapacity of the chiller (both of which can be sized to meet the demandsof a particular fueling station) and the temperature class requirementsof the fueling station.

As discussed above, using a large-volume reservoir as a thermal bufferallows the use of a small-capacity refrigeration unit that can be sizedfor average as opposed to peak load, facilitating a highly scalablecooling system that can be configured to meet the demands of fuelingstations with different performance requirements. This scalabilityallows cooling systems that can service light, medium and heavy-dutyfueling requirements at a lower cost. The large-volume reservoir andsmall-capacity refrigeration unit also facilitates a wide variety ofconfiguration options such a single coolant reservoir for multiple heatexchanger/nozzle pairs, shared heat exchangers for multiple nozzles,multiple coolant reservoirs for a single refrigeration unit, etc.,examples of which are described in further detail below.

As discussed above, costs may be also be reduced by replacingconventional diffusion bonded (plate-to-plate) heat exchangers with anannular heat exchanger that has been adapted to operate in the highpressure and high UA hydrogen fueling environment. By providing a lowercost high UA heat exchanger, scalability and flexibility of a hydrogencooling system can be further improved. For example, conventional bondedheat exchangers are costly, making employing a single heat exchanger asignificant expense that often renders scaling up cost prohibitive. Bycontrast, an annular heat exchanger can be provided at significantlyreduced cost and facilitate configurations in which an annular heatexchanger may be provided for each nozzle dispenser at a fuelingstation, or shared between dispensers at each refueling island, examplesof which are described in further detail below.

FIGS. 14A illustrates an annular high UA heat exchanger for hydrogenrefueling using a shell-and-tube configuration, in accordance with someembodiments. Exemplary annular high UA heat exchanger 400 comprises ashell 410 through which coolant is circulated via coolant inlet 415 aand coolant outlet 415 b in the direction generally indicated by arrow417. For example, coolant from a coolant reservoir may be pumped in viainlet and 415 a and returned to the reservoir or provided to a chillervia outlet 415 b, depending on the configuration of the hydrogen coolingsystem. As shown in FIG. 14B, a coil 450 formed of a metal or metalalloy tubing (e.g., nickel, nickel alloy, copper, copper alloy oranother type of alloy, etc.) is positioned within the shell throughwhich hydrogen gas is pumped via hydrogen inlet 405 a and hydrogenoutlet 405 b. For example, hydrogen gas from the hydrogen gas source ofthe fueling station may be pumped into coil 450 via inlet 405 a in thedirection generally indicated by arrow 407 and provided via outlet 405 bto a dispenser nozzle to refuel a HFCV. As illustrated schematically byarrows 407 and 417, hydrogen gas and coolant are pumped through heatexchanger 400 in a counter-flow arrangement to facilitate heat transferfrom the hydrogen gas to the coolant. Heat exchanger 400 also includesPRD port 413 to and thermocouple 420.

FIG. 14B illustrates annular heat exchanger 400 without the outer shell,illustrating the tubing of coil 450 wrapped about baffle 460. Byproviding the tubing with multiple turns or wraps, hydrogen gas can bepumped through a long length of tubing with significant surface areaexposure to coolant flowing through the shell, allowing for high UA heatexchange in a relatively compact space. According to some embodiments,the tubing for coil 450 has a total length of between 30 and 50 feet andcomprises between 20 and 35 turns or wraps. However, it should beappreciated that the number of wraps of the tubing forming coil 450 maybe configured to meet the requirements of a given heat exchanger and arenot limited to the exemplary values provided herein. Heat exchanger 400also includes baffle 460 to force the coolant through a relatively tightarea, increasing both the velocity and turbulence of the coolant topromote heat transfer and increase the heat transfer efficiency of theheat exchanger. Baffle 460 may be provided with a series of pilot holesto prevent air pockets or “dead zones” from forming along the bafflethat could reduce the heat transfer efficiency of the exchanger.

FIG. 14C illustrates a view of tubing 450 showing a turn at a inlet sideof the coil to illustrate exemplary dimensions of the tubing. As shown,tubing 450 has an outer diameter OD, inner diameter ID and a wallthickness t. According to some embodiments, tubing 450 has an outerdiameter of between 4.5 and 5.5 inches, an inner diameter of between 3and 4 inches, and a thin wall thickness between 0.03 and 0.08 inches,and more preferably between 0.04 and 0.06 inches (whereas conventionalwall thicknesses are on the order of 0.1 inches, which generallyprovides inefficient heat transfer that is generally not sufficient forhydrogen refueling without significantly increasing the length of thecoil tubing) to increase heat transfer efficiency. However, thedimensions of tubing 450 may be scaled up or down and the individualparameters may be chosen to meet the requirements of a given heatexchanger and are not limited to the exemplary values described hereinfor the illustrative embodiments illustrated.

FIGS. 14D and 14E illustrate top view and a side views of heat exchanger400, respectively, illustrating the positioning of coil 450 within shell410 that is wrapped about baffle 460 to provide a high UA heat exchangerin accordance with some embodiments. Heat exchanger 400 has a length Land a height H (that includes the height of feet 470 a and 470 b).

According to some embodiments, the length L may be between 30 and 50inches (e.g., approximately 38-39 inches) and the H is between 10 and 15inches (e.g., approximately 12-13 inches). However, the dimensions ofheat exchanger 400 may be chosen to meet the requirements of a givenheat exchanger and are not limited to the exemplary values described forthe exemplary embodiments illustrated herein.

According to some embodiments, coil 450 is made of a material that iscompatible with hydrogen and that is capable of withstanding thepressure conditions of hydrogen refueling at thin wall thickness, suchas a nickel alloy or the like. For example, a nickel alloy material isresistant to corrosion and is therefore suitable for the hydrogenrefueling environment. As discussed above, to increase heat transferefficiency, coil 450 may be manufactured with a thin wall thickness(e.g., t equal to approximately 0.044 inches) to reduce the amount ofmaterial between the hydrogen and the coolant. Using a thin wallthickness facilitates a more compact design for the heat exchanger byreducing the length of tubing needed to achieve the amount of cooling.For example, conventional tube thicknesses on the order of 0.1 inchesrequired doubling or tripling the length of the tubing needed to achievesuitable cooling for many hydrogen refueling applications. Thin wallthickness for the tubing also reduces the time to cool hydrogen totarget temperatures. Hydrogen refueling applications often have shortwindows (e.g., approximately 30 seconds) to hit the temperature targetfor the hydrogen and providing a thin wall thickness for the tubingreduces the time to cool the hydrogen to target.

In addition, coil 450 may be finned to increase the surface area of thecoil to substantially increase the heat transfer efficiency. FIG. 15illustrates a coil that has been finned to create more surface area viawhich heat from the hydrogen gas flowing through the tubing can betransferred to the coolant flowing through the shell in which the coilis positioned (e.g., in the exemplary configuration illustrated in FIGS.14A-E). In particular, circular or elliptical fins are attachedcircumferentially to provide fins about the tubing that are spaced apartalong the length of the coil to provide additional surface area for heatexchange between hydrogen gas pumped through the tubing and coolantpumped through the shell. In the embodiment illustrated in FIG. 15,copper fins (e.g., exemplary copper fins 455) are attached to tubing 450to provide a plurality of transverse fins around and in contact with thetubing at a relatively small spacing along the length of the coil.According to some embodiments, multiple fins 455 (or all of the fins)may be formed by a single continuous coil that spirals about tubing 450to provide a finned coil for the heat exchanger. Finning coil 450 canincrease the heat transfer capacity from approximately 5 kW to 75 kW,facilitating the provision of a high UA heat exchanger for hydrogenrefueling.

Finning of tubing 450 may be achieved by attaching the fins to thetubing using a brazing process. The inventors recognized that hightemperature brazing can result in annealing of the metal during thebrazing process, thereby reducing the strength of the material resultingin the risk of rupturing during use under the high-pressure conditionsof hydrogen fueling. According to some embodiments, a silver alloy brazeis used that allows fins to be attached to the tubing at relatively lowtemperatures that prevents annealing of the metal materials during thebrazing process, thereby maintaining the integrity of the coil. A silveralloy braze is also compatible with coil and fin materials, for example,nickel alloy tubing and copper fins. According to some embodiments,finning and bending of the tubing into a coil is performed during thesame process. Table I illustrates materials and parameters for anexemplary coil (e.g., coil 450) for an annular high UA heat exchangersuitable for hydrogen fueling applications, in accordance with someembodiments. It should be appreciated that the materials and valuesgiven in Table I are merely exemplary and that different materials anddifferent values may be used to provide the coil for an annular high UAheat exchanger, as the aspects are not limit to any particular choice ofmaterial, dimensions and/or values for the coil.

TABLE I Tubing Material Nickel Alloy Total Length 35 feet Coil Length17.375 inches Number of Wraps 27 Pitch .625 inches Outer Diameter 4.9inches Inner Diameter 3.6 inches Wall Thickness .044 inches Fin MaterialCopper Braze Silver Alloy Heat Transfer Capacity 75 kW

According to some embodiments, an annular heat exchanger is providedwithout the outer shell (FIGS. 16C, 16D) and/or without a baffle (FIGS.16D, 16E) to facilitate different configurations of heat exchangers,examples of which are described in further detail below. FIG. 16Aillustrates the cross-section of an annular high UA heat exchangerillustrating the annular configuration of heat exchanger 400 illustratedin FIGS. 14A-F. In particular, the exemplary configuration illustratedin FIG. 16A comprises outer shell 410 containing heat exchanger coil 450positioned about baffle 460. The return tube 455 for the cooled hydrogengas is passed through the center of heat exchanger and provided to theoutlet of the heat exchanger for dispensing to the vehicle. FIG. 16Billustrates the cross-section of an annular high UA heat exchangerhaving an outer coil 450 a and an inner coil 450 b to increase the heattransfer capacity of the annular heat exchanger. The components of theheat exchanger whose cross-section is illustrated in FIG. 16B may bescaled up to provide a larger-sized heat exchanger with increased heattransfer capacity for fueling stations having higher performancerequirements (e.g., fueling stations for some medium-duty or heavy-dutyinstallations for which very high performance is needed).

FIGS. 16C and 16D illustrate the cross-section of embodiments of annularheat exchangers without an outer shell for the single coil and multiplecoil configurations, respectively. In particular, the cross-section ofthe annular heat exchanger illustrated in FIG. 16C comprises a coil 450and baffle 460 with the return path 455 for the hydrogen passing throughthe center, and the cross-section of the annular heat exchangerillustrated in FIG. 16C comprises outer coil 450 a and inner coil 450 b,both implemented without an outer shell. FIGS. 16D and 16E illustratethe cross-section of embodiments of annular heat exchangers both withoutan outer shell and a baffle for the single coil and multiple coilconfigurations, respectively. In particular, the cross-section of theannular heat exchanger illustrated in FIG. 16D comprises a coil 450 withthe return path for the hydrogen passing through the center, and thecross-section of the annular heat exchanger illustrated in FIG. 16Ecomprises outer coil 450 a and inner coil 450 b, both without and outershell or baffle. It should be appreciated that multiple coilconfigurations may have additional coils, as the aspects are not limitedto the number of coils provided. The coils may be formed using any ofthe techniques described above in any combination.

As discussed above, annular high UA heat exchangers facilitate reducingthe cost of a hydrogen cooling system of a fueling station.Additionally, the reduced cost annular heat exchanger improves theflexibility and/or scalability of a hydrogen cooling system that can beconfigured to meet the needs and requirements of a given fuelingstation. FIG. 18 illustrates a hydrogen fueling system utilizing ahydrogen cooling system comprising a refrigeration unit configured toprovide cooling for a coolant reservoir that is shared by multipledispensers, wherein each dispenser has a respective high UA heatexchanger, which are preferably annular heat exchangers configuredaccording to one or more techniques described in the foregoing. Inparticular, a dispenser island 1800 of a fueling station comprises afirst dispenser 1820 a and a second dispenser 1820 b. A large-volumecoolant reservoir 814 comprising insulated tank 817 capable of holding alarge volume of coolant (e.g., a 50-600 gallon tank, and more preferablybetween 80-120 gallons) is positioned between the first and seconddispensers to store coolant to chill hydrogen gas prior to beingdispensed by dispensers 1820 a and 1820b to a fuel tank of an HFCV. Asingle small-capacity refrigeration unit 812 (e.g., a refrigeration unithaving a heat rejection capacity of between 1 kW and 21 kW, and morepreferably less than 10 kW) is provided for dispenser island 1800 tomaintain the coolant at low temperatures via refrigeration coil 813(e.g., between −40° C. and −17.5° C.). Refrigeration unit 812 may besized to handle the average load of the fueling station because thelarge-volume insulated tank operates as a substantial thermal buffer.For example, a fueling station with a relatively small average load mayimplement the hydrogen cooling system using a 1 kW capacityrefrigeration unit, while a fueling station with larger average loadsmay implement the hydrogen cooling system using a higher capacityrefrigeration unit (e.g., 3 kW, 7 kW, 10 kW, etc.) depending on theaverage load of the fueling station and/or on the performancerequirements of the fueling station. In this way, the hydrogen coolingsystem can be scaled up to meet the needs of a given fueling station.According to some embodiments, the small-capacity refrigeration unit maybe sized to up to 21 kW (e.g., 12 kW, 15 kW, 20 kW, etc.) and thereservoir may be sized up to 600 gallons or more for some medium orheavy-duty fueling applications.

The hydrogen cooling system further comprises an annular high UA heatexchanger for each of dispensers 1820 a and 1820 b. Specifically, in theexemplary embodiment illustrated in FIG. 18, annular heat exchanger 816a is fluidly coupled to dispenser 1820 a and annular heat exchanger 816b is fluidly coupled to dispenser 1820 b so that chilled hydrogen can bedispensed via nozzles 1825 a and 1825 b, respectively. To providehydrogen gas at targeted temperatures for refueling, each heat exchanger816 a, 816 b is also fluidly coupled to a hydrogen gas source 805 at thefueling station and coupled to coolant held in insulated tank 817 ofcoolant reservoir 814 shared by dispensers 1825 a and 1825 b. Coolantreservoir 815 may comprise one or more pumps 815 that circulate chilledcoolant held in insulated tank 817 through the heat exchangers. One ormore pumps may also be provided to pump hydrogen gas from hydrogen gassource 805 through heat exchangers 816 a and 816 b when respectivedispenser nozzles 1825 a and 1825 b are engaged with the fuel tank of anHFCV for fueling and/or hydrogen gas may flow through heat exchangers1825 a and 1825 b via the pressure gradient at hydrogen source 805. Inthe exemplary embodiment illustrated in FIG. 18, the heat exchangers areillustrated as located within the insulated tank. However, the heatexchanger may be located external to the reservoir (e.g., as illustratedin FIG. 11). Placement of the heat exchanger (e.g., internal or externalto the tank) may depend on the specific design configuration of aparticular fueling station, and the aspects are not limited to anyparticular placement of the heat exchangers.

As discussed above, heat exchanger 816 a, 816 b are preferably annularheat exchangers including any one or combination of features describedherein. According to some embodiments, heat exchangers 816 a and 816 bmay comprise a finned coil of tubing made of a material compatible withhydrogen (e.g., nickel alloy tubing with copper fins) designed for highheat transfer efficiency. For example, the coil of tubing may be formedwith thin walls (e.g., less than 0.07 inches, and more preferably lessthan 0.05 inches) to facilitate a high heat transfer of capacity (e.g.,a heat transfer capacity of greater than 25 kW and more preferablygreater than 50 kW, such as a heat transfer capacity of approximately 75kW or more). According to some embodiments, annular heat exchangers 816a and 816 b each comprise multiple coils to increase the heat transfercapacity of the heat exchanger. It should be appreciated that heatexchangers 816 a and 816 b may be dimensioned in any manner suitable forthe given fueling station, as the aspects are not limited to anyspecific annular heat exchanger design. Additionally, heat exchangers816 a and 816 b may have the same or different design from one anotherto achieve desired dispensing characteristics of the dispenser to whichit is coupled.

Hydrogen gas source 805 may be one or more hydrogen gas storage tanksshared by all of the dispensers at the fueling station, shared by asubset of the dispensers at the fueling station or may comprise multipleindividual hydrogen gas storage tanks at each of the dispensers (whichmay in turn receive hydrogen gas from a primary hydrogen storage tank orsource, or may be standalone dispenser units), as the aspects are notlimited to any particular configuration for the hydrogen gas source. Inthe exemplary embodiment illustrated in FIG. 18, dispensers 1820 a and1820 b are separate dispenser units (e.g., implemented within separatehousings and separate dispenser controllers), however, according to someembodiments, dispensers 1820 a and 1820 b may be implemented as a singleunit (e.g., within a single housing) having multiple nozzles, as theaspects are not limited in this respect. Dispenser 1820 a and 1820 b maybe conventional dispensers or may be dispensers configured with theinnovative dispenser controllers and/or valves described in furtherdetail below. The above-described configuration provides a compacthydrogen cooling system that can be implemented on a per island basis toprovide hydrogen cooling for multiple nozzles. This configuration may berepeated for each island at the fueling station. According to someembodiments, refrigeration unit 812 may be integrated in a singlehousing with reservoir 914 between the dispensers, may be positionedadjacent to reservoir 914, or reservoir 914 may be integrated withinrefrigeration unit 812 (e.g., as illustrated in FIG. 17), as the aspectsare not limited in this respect. According to some embodiments,refrigeration unit 812 may be coupled to reservoirs at more than oneisland. It should be appreciated that the components of the hydrogenfueling system illustrated in FIG. 18 (as with all of the systemsdescribed herein) are not drawn to scale and are not intended toindicate relative sizes of the components, but rather to show thecoupling and arrangement of these components.

The hydrogen cooling system may either be coupled upstream or downstreamfrom flow control valves 1880 a and 1880 b of the respective dispensers.The two different hydrogen flow paths for upstream and downstreamconfiguration are illustrated in solid and dotted lines, respectively.Specifically, as shown by the solid lines, according to some embodimentsin which the hydrogen cooling system is coupled upstream of the flowcontrol valve, hydrogen gas from hydrogen gas source 805 is provided tothe inlet of heat exchangers 816 a, 816 b and chilled hydrogen gas fromthe heat exchangers is provided to flow control valves 1880 a and 1880b, respectively. Chilled hydrogen gas flowing through the flow controlvalves is provided to nozzle 1825 a and 1825 b for dispensing to avehicle during a fueling event. As shown by the dotted lines, accordingto some embodiments the hydrogen cooling system is coupled downstream ofthe flow control valve, hydrogen gas from hydrogen gas source 805 isprovided to flow control valves 1880 a, 1880 b and hydrogen gas flowingthrough the flow control valves is provided to the inlet of heatexchangers 816 a, 816 b respectively. Chilled hydrogen gas from the heatexchangers is provided to dispenser nozzles 1825 a, 1825 b fordispensing to a vehicle during a hydrogen fueling event. This solid anddotted line convention is also used in the embodiments illustratedherein to illustrate that either upstream or downstream coupling of ahydrogen cooling system can be used in any configuration that utilizes ahydrogen cooling system. As used herein, when a heat exchanger isdescribed as providing hydrogen gas to the dispenser, it refers to bothupstream configurations in which hydrogen gas from the heat exchanger isprovided to the dispenser upstream of the flow control valve anddownstream configuration in which hydrogen gas from the heat exchangeris provided to the dispenser downstream of the flow control valve.

FIG. 19 illustrates a hydrogen fueling system utilizing a hydrogencooling system comprising a refrigeration unit configured to providecooling for a coolant reservoir that is shared by multiple dispensers,in accordance with some embodiments. The exemplary hydrogen fuelingsystem illustrated in FIG. 19 may be similar in one or more respects tothe hydrogen fueling system described in connection with FIG. 18. InFIG. 19, a small-capacity refrigeration unit 912 is provided to chillcoolant (e.g., via refrigeration coil 913) held in large-volumereservoir 914 comprising insulated tank 917 shared by dispensers 1920 aand 1920 b on dispenser island 1900. In the embodiment illustrated inFIG. 19, dispensers 1920 a and dispenser 1920 b share a single heatexchanger 916. Specifically, a single heat exchanger is fluidly coupledto hydrogen source 905 and coupled to coolant held in tank 917 to chillhydrogen gas when hydrogen from hydrogen source 905 and coolant from thetank circulate through the heat exchanger. An outlet of heat exchanger916 is fluidly coupled to both dispensers to provide chilled hydrogen tonozzles 1925 a and 1925 b for refueling. The individual components ofthe hydrogen refueling system illustrated in FIG. 19 may be implementedusing any of the techniques described herein. According to someembodiments, heat exchanger 916 may be a high UA annular heat exchanger(e.g., any of the annular heat exchangers described in the foregoing) toprovide a lower cost solution to chilling hydrogen). However, accordingto some embodiments, heat exchanger 916 may be another type of high UAheat exchanger such as a diffusion-bonded heat exchanger, as the aspectsare not limited in this respect. The components of the hydrogen coolingsystem can be arranged apart, proximate or adjacent, in the same housingor integrated together in any of the configurations discussed in theforegoing (e.g., as described in connection with the hydrogen fuelingstation illustrated in FIG. 19).

FIG. 20 illustrates a hydrogen fueling system utilizing hydrogen coolingsystem comprising a refrigeration unit configured to provide cooling fora plurality of coolant reservoirs corresponding to respectivedispensers, in accordance with some embodiments. The exemplary hydrogenfueling system illustrated in FIG. 20 may comprise individual componentsthat are the same as or similar to the components described inconnection with FIGS. 18 and 19 that are sized appropriately for theconfiguration illustrated in FIG. 20. In this configuration, asmall-capacity refrigeration unit 2012 is coupled to a first coolantreservoir 2014 a comprising insulated tank 2017 a and a second coolantreservoir 2014 b comprising insulated tank 2017 b, each coolantreservoir servicing a respective dispenser 2020 a and 2020 b. Each ofdispensers 2020 a and 2020 b has its own heat exchanger 2016 a, 2016 b(preferably of the annular heat exchanger type), respectively, to chillhydrogen gas from hydrogen source 2005 and provide the chilled hydrogento respective dispenser nozzle's 2025 a and 2025 b.

As discussed above, it should be appreciated that the exemplary hydrogenfueling systems shown in FIGS. 18-20 are illustrated schematically andthe relative sizes of the components are not drawn to scale but areintended instead merely illustrate a set of components and couplingtherebetween to illustrate an exemplary configuration using one or moreaspects of the techniques developed by the inventors to implement aflexible and highly scalable hydrogen cooling system for a wide range ofhydrogen fueling applications from light duty to medium and heavy dutydeployments. It should be further appreciated that the small-capacityrefrigeration unit, large-volume coolant reservoir and high UA heatexchanger combination of components is amenable to other configurationssuitable for a given fueling station and that the components can besized and configured as discussed herein to scale up or down to meet theperformance requirements of a particular fueling station installment.

As discussed above, the inventors have further appreciated that thethermal energy capacity of a hydrogen cooling system may be increased byusing phase change materials (PCM) as a coolant, either alone or inconjunction with one or more other coolants. As also discussed above,phase change materials store energy when cooled so that the materialtransitions from one state to another (e.g., from a liquid to a solid,or from a gas to a liquid) that can be released upon when the materialis heated so as to transition back to the previous state (e.g., from asolid to a liquid, or from a liquid to a gas). As a result, heattransferred from hydrogen gas during the chilling process for a fuelingevent goes into state change rather than heating up the material. Thus,a PCM coolant can be used like a thermal battery that can be“charged-up” by causing it to transition from its ambient temperaturestate to its low temperature state, and that stored thermal energy canbe released as the PCM absorbs heat from hydrogen gas (or anothercoolant that has absorbed heat from hydrogen gas) that goes intochanging the state of the PCM back to its ambient temperature state.Therefore, a reservoir of PCM material can absorb more heat fromhydrogen gas (or another coolant that has absorbed heat from hydrogengas) without increasing its temperature, allowing for longer periods ofcontinuous hydrogen chilling without needing to recover the temperatureof the PCM and/or other coolant in the reservoir.

In addition, PCM material provides better thermal control over thehydrogen gas because it will maintain the temperature of its lowtemperature state transition until the material has transitioned back toits ambient temperature state. As discussed above, back-to-back fills(i.e., without a recovery period) using conventional coolants result inincreasingly higher temperature hydrogen gas fills until the maximumtemperature at which hydrogen gas can be dispensed is reached and nofurther fueling can take place until the refrigeration unit recovers thetarget temperature of the coolant in the reservoir. Because thetemperature of the PCM will be maintained at its low temperature statetransition temperature, back-to-back fills can be performed at thattemperature until the PCM has been thoroughly transitioned to itsambient temperature state.

The inventors have recognized that PCMs can therefore be used tooptimize the hydrogen cooling system for specific hydrogen fueling needsin a number of ways, including increasing the number of back-to-backfills that can be performed, reducing the size of the coolant reservoir,reducing the size of the refrigeration unit (which can be operatedduring the night or other off-peak hours when demand is low and/orenergy is cheaper to bring the PCM to its low temperature state), orsome combination of the above, as discussed in further detail below.

FIG. 21 illustrates an example a hydrogen cooling system using a PCM asa coolant to chill hydrogen gas, in accordance with some embodiments.Hydrogen cooling system 2100 comprises a refrigeration unit 2112 thatchills coolant stored in a reservoir 2114 comprising insulated tank 2117to hold PCM coolant, components that may be similar or the same as, ordifferent from, those described in the foregoing and that, in accordancewith some embodiments, can be optimally sized in different ways as aresult of the use of PCM. Refrigeration unit 2112 is configured to chillthe PCM coolant to a temperature that causes the PCM to transition toits low temperature state, e.g., via refrigeration coil 2113 or via anyother refrigeration techniques, thereby storing energy by the transitionof the PCM to its low temperature state.

According to some embodiments, the PCM's low temperature state is as asolid so that refrigeration unit 2112 freezes the PCM material to bringthe reservoir down to the target temperature. In such embodiments, heatexchanger 2116 may be an annular heat exchanger comprising one or morecoils according to techniques described herein, but with no outer shell(e.g., as shown in the exemplary configurations illustrated in FIGS.16C-F. In such a configuration, the coil(s) of heat exchanger 2116 maybe positioned within the reservoir in contact with the PCM that in thelow temperature state will form a solid mass about the coil to absorbheat from hydrogen gas provided by a hydrogen gas source to an inlet ofthe heat exchanger to provide chilled hydrogen gas to one or moredispensers of a fueling station. As discussed above, the use of a PCMreservoir allows an increased number of back-to-back fills to beachieved without increasing the temperature of the PCM due to theincreased thermal capacity of the PCM (i.e., absorbed heat energy goesinto changing the state of the PCM instead of increasing itstemperature). The increased thermal capacity of the PCM reservoir alsoallows the volume of the reservoir to be reduced and/or the capacity ofthe refrigeration unit 2112 to be reduced, thereby providing a morecompact and/or less expensive hydrogen cooling system. According to someembodiments, the PCM is a eutectic compound (e.g., a mixture ofmaterials) that has a state transition at approximately the temperatureof the lowest temperature class fill at which the dispenser isconfigured to dispense hydrogen gas (e.g., approximately −40° C. for T40class fills). However, it should be appreciated that such PCMs may bechosen to have other low temperature state transitions (e.g., less than−10° C., less than or equal to −20° C., less than or equal to −30° C.,less than or equal to −40° C., etc.), as the aspects are not limited inthis respect.

With respect to the refrigeration unit 2112, because the PCM reservoirdoes not need to be brought back to the target temperature asfrequently, a smaller capacity refrigeration unit can be utilized andoperated relatively infrequently when the PCM reservoir needs to bebrought back to its low temperature state. For example, therefrigeration unit may be operated overnight or during off hours (e.g.,when energy is cheaper), when substantially all of the PCM hastransitioned to its ambient temperature state (e.g., before or after thetemperature of the ambient PCM has reached a temperature in which nofurther low temperature fills can be performed) and/or when the fuelingstation determines recovering the temperature and/or low temperaturestate of the PCM is needed via the vehicle communication techniquesdescribed above. The above described benefits (increasing theback-to-back fill capacity, reducing the volume of the reservoir,reducing the capacity of the refrigeration unit, increasing the numberof reservoirs coupled to the refrigeration unit and/or increasing thenumber of dispenser nozzles sharing the reservoir) can be used in anycombination, thus providing a highly flexible and modular hydrogencooling system that can meet the needs of a wide variety of fuelingstations, including providing different configurations of components fordifferent dispenser islands within the same fueling station, providingmultiple independent hydrogen cooling systems within the same fuelingstation, or a single hydrogen cooling system configured for light,medium or heavy duty refueling needs.

The inventors have further recognized that PCMs can be used incombination with conventional coolants in a variety of ways to takeadvantage of the increased thermal capacity of PCMs. According to someembodiments, a dual-stage hydrogen cooling system is provided comprisinga bulk PCM reservoir for storing a PCM to chill hydrogen gas from ahydrogen source to a first temperature and a polishing reservoir forstoring a conventional (non-PCM) coolant (e.g., glycol) to chillhydrogen gas from the bulk PCM reservoir to a second temperature fordispensing to a HFCV during a fueling event. According to someembodiments, a coolant reservoir combines a conventional coolant and aPCM material to take advantage of the increased thermal capacity of thePCM when brought to its low temperature state. According to someembodiments, a PCM is integrated into the heat exchanger (e.g., within abaffle of annular heat exchanger) configured to also circulate aconventional coolant to chill hydrogen gas via both the integrated PCMand the circulated conventional coolant. Examples of hydrogen coolingsystems utilizing one or more these techniques is discussed in furtherdetail.

FIG. 22 illustrates an exemplary dual-stage cooling system comprising abulk PCM reservoir 2214 a that includes an insulated tank 2217 a forstoring a PCM having a phase change at a first temperature (e.g.,between −20° C. and −10° C., between −10° C. and 0° C., etc.), and apolishing reservoir 2214 b that includes an insulated tank 2217 b forstoring a conventional coolant. In the exemplary embodiment illustratedin FIG. 22, a refrigeration unit 2112 is coupled to PCM reservoir 2214 ato chill the PCM to cause a phase change of the PCM (e.g., viarefrigeration coil 2213 a) at the first temperature, and therefrigeration unit 2112 is also coupled to polishing reservoir 2214 b tochill the conventional coolant to a target temperature for hydrogen gasdispensing (e.g., via refrigeration coil 2213 b). Bulk PCM reservoir2214 a may further comprise annular heat exchanger 2216 a coupled toreceive hydrogen gas from a hydrogen source (which may either be ahydrogen gas storage tank or a dispenser depending on whether hydrogencooling is coupled upstream or downstream of the dispenser flow controlvalve) and provide chilled hydrogen at the first temperature via heatexchange between the hydrogen gas and the PCM as the hydrogen gas flowsthrough one or more coils of heat exchanger 2216 a. A second annularheat exchanger 2216 b may be coupled to coolant held by polishingreservoir 2214 b and hydrogen gas provided by annular heat exchanger2216 a to chill the hydrogen gas from the first temperature to a targettemperature for dispensing to an HFCV. Second annular heat exchanger maybe deployed internal to polishing reservoir 2214 b or may be deployedexternal to the polishing reservoir as discussed in the foregoing.

Annular heat exchanger 2216 a may be formed using one or more coilsusing any of the techniques described above so that the one or morecoils are thermally coupled to the PCM (e.g., in contact with the PCM),for example, using the annular configurations illustrated in FIGS. 16C-Fthat do not include an outer shell. Thus, for exemplary dual-stagehydrogen cooling system 2200, a first stage chills hydrogen gas fromhydrogen gas source to a first intermediate temperature between thetemperature of the stored hydrogen gas at the source and the targettemperature for dispensing to a HFCV, and a second stage chills hydrogengas from the intermediate temperature to the target temperature fordispensing. The use of a bulk PCM reservoir for chilling hydrogen to anintermediate temperature allows generally less expensive PCMs to be usedand allows for flexibility in the choice of PCM. Because polishingreservoir need only reduce the temperature of hydrogen gas from theintermediate temperature to the target temperature rather than all theway from the temperature of the hydrogen gas from the hydrogen source,each fueling event requires less energy to cool the hydrogen gas,reducing the temperature increase of the coolant from each fill, therebydecreasing recovery times and increasing the back-to-back fill capacityof the hydrogen cooling system.

In the exemplary embodiment illustrated FIG. 22, a single refrigerationunit is employed to chill both the bulk PCM reservoir and the polishingreservoir. However, according to some embodiments, differentrefrigeration units are used to chill the bulk PCM reservoir and thepolishing reservoir, respectively, or different stages of a multi-stage(e.g., cascaded) refrigeration unit may be used to chill the differentstages of the hydrogen cooling system. Additionally, it should beappreciated that the coupling of the refrigeration unit 2112 to thereservoirs illustrated in FIG. 22 is schematic to illustrate thatrefrigeration unit 2112 provides refrigeration for both reservoirs, butthat refrigeration unit 2112 may be coupled to stages of the hydrogencooling system so that the reservoirs can be chilled independently ofone another. For example, refrigeration unit 2112 may be independentlycoupled to bulk PCM reservoir 2214 a and polishing reservoir 2214 b sothat the stages can be independently cooled. Because bulk PCM reservoir2214 a may only need to infrequently recover the low temperature stateof the PCM, it may be advantageous to be able to chill the bulk PCMreservoir and the polishing reservoir independently. According to someembodiments, the stages of the hydrogen cooling system may be chilledsimultaneously, as the aspects are not limited in this respect.

According to some embodiments, a single bulk PCM reservoir providesintermediate cooling for multiple polishing reservoirs. For example, asingle bulk PCM reservoir may provide intermediate cooling for aplurality of polishing reservoirs where each of the plurality ofpolishing reservoirs are shared by multiple dispensers of a dispenserisland, or where each of the plurality of polishing reservoirs is usedby a single respective dispenser. The flexibility of dual-stage hydrogencooling systems allows for many different configurations andoptimizations for both the sizing of the one or more refrigeration unitsand for the volume of both the PCM reservoir and the one or morepolishing reservoirs to meet the needs of a particular fueling station.It should be appreciated that the use of a multi-stage cooling systemcan be implemented in other configurations and the aspects are notlimited to any particular configuration, combination of elements and/ortypes of PCM and conventional coolants.

FIG. 23 illustrates an exemplary annular heat exchanger configured tohold a PCM internally to take advantage of the increased thermalcapacity of PCMs to chill hydrogen flowing through one or more coils ofthe heat exchanger, in accordance with some embodiments. Annular heatexchanger 2316 may share similar aspects to the annular heat exchangersdescribed in connection with FIGS. 14D-E and 15. Specifically, exemplaryannular heat exchanger 2316 comprises an outer shell 2310 through whichcoolant can be circulated via coolant inlet 2315 a and coolant outlet2315 b, and an inner coil 2350 (e.g., a finned coil of tubing) throughwhich hydrogen gas can be circulated via hydrogen inlet 2305 a andhydrogen outlet 2305 b. For annular heat exchanger 2316, inner portion2360 is configured to hold a PCM material 2321 (e.g., a baffle may beconfigured to store PCM) such that inner coil 2350 is thermally coupledto PCM 2321 when the inner portion 2360 contains the PCM. As a result,hydrogen gas flowing through coil 2350 transfers heat to bothconventional coolant circulating through the heat exchanger and PCM 2321held internally. It should be appreciated that PCM may be held internalto the heat exchanger in other ways, as the aspects are not limited inthis respect.

FIG. 24 illustrates an exemplary hydrogen cooling system that utilizesan annular heat exchanger of the type described above in connection withFIG. 23, in accordance with some embodiments. In particular, hydrogencooling system 2400 comprises reservoir 2414 that includes insulatedtank 2417 configured to hold a conventional non-PCM coolant. Hydrogencooling system 2400 further comprises annular heat exchanger 2416configured to hold a PCM material, for example, using an inner portionof the heat exchanger as described in connection with heat exchanger2316 illustrated in FIG. 23. Heat exchanger 2416 may be coupled toreceive hydrogen gas from a hydrogen gas source via an inlet to one ormore coils of the heat exchanger, and further coupled to receive non-PCMcoolant from the reservoir to circulate the coolant through the heatexchanger to absorb heat energy from the hydrogen gas flowing throughthe coil.

Refrigeration unit 2412 may be coupled to reservoir 2414 to chill thenon-PCM coolant in insulated tank 2417 (e.g., via refrigeration coil2413 or other refrigeration techniques) and the PCM within heatexchanger 2416. When hydrogen gas and coolant are pumped through heatexchanger 2416, heat from the hydrogen gas is absorbed by the coolantand the PCM held internal to the heat exchanger. As such, the heattransfer load of a fueling event will be shared by the PCM and non-PCMcoolants, resulting in a reduction in the temperature increase of thenon-PCM coolant in the reservoir. Therefore, the exemplary PCM techniqueused by hydrogen cooling system can be used to increase the back-to-backfill capacity of the fueling system, decrease the recovery time of thecoolant reservoir, allow for a reduction in the size of therefrigeration unit and/or volume of the reservoir, or facilitate anoptimization that achieves some combination of these benefits. It shouldbe appreciated that exemplary hydrogen cooling system 2400 may be usedin any of the variety fueling system configurations described herein(e.g., the hydrogen fueling systems illustrated in FIGS. 18-21) allowingfor further optimization and customization of the resulting hydrogenfueling system.

FIG. 25 illustrates another exemplary hydrogen cooling system utilizingPCMs to increase the thermal energy capacity of a coolant reservoir, inaccordance with some embodiments. Fueling system 2500 may utilize asimilar configuration as exemplary fueling system 1700 described inconnection with FIG. 17 in that a coolant reservoir is integrated with arefrigeration unit to form an integrated chiller system. In particular,in the embodiment illustrated in FIG. 25, a chiller system includes arefrigeration unit comprising an evaporator and a condenser that chillscoolant held in integrated reservoir 2514. Reservoir 2514 may beconfigured to hold both a PCM and a conventional (non-PCM) coolant andchiller system 2512 is arranged to chill both the PCM and theconventional coolant held in the reservoir. For example, reservoir 2514may contain both a low temperature eutectic PCM and a conventionalcoolant such as glycol that are chilled to a target temperature thatcauses the PCM to transition to its low temperature state (e.g., asolid). A heat exchanger 2516 may be coupled to chiller system 2512 andhydrogen gas source 2505 to chill hydrogen gas with coolant pumped fromreservoir 2514 and circulated through the heat exchanger via supply andreturns lines. The chilled hydrogen gas may then be provided to one ormore dispensers 2520 for fueling of HFCVs. The increased thermal energycapacity of the PCM is capable of providing benefits described in theforegoing. It should be appreciated that a coolant reservoir containingboth PCM and conventional coolant may be used in any of the otherconfigurations described above and is not limited for use in theintegrated chiller system illustrated in FIG. 25 (e.g., as a separatecoolant reservoir as illustrated in FIGS. 18-20, for example).

FIGS. 26A and 26B illustrate coaxial tubing that includes PCM tofacilitate aspects of hydrogen gas cooling, in accordance with someembodiments. FIG. 26A illustrates a cross-section of coaxial tubing 2675that can be used to transport hydrogen from components of a fuelingstation to one or more dispensers to provide chilled hydrogen todispensers for delivery to the fuel tank of an HFCV during a fuelingevent. In the embodiment illustrated in FIG. 26, coaxial tubing 2675comprises three concentric tubes: an inner tube 2650 through whichhydrogen gas can flow; a middle tube 2660 to contain a PCM; and outertube 2670 through which a conventional (non-PCM) coolant can flow. Innertube 2650 may be the same or similar to conventional piping used totransport hydrogen between components of the fueling system or mayinclude a different type of tubing. It should be appreciated that therelative diameters of the different tubing levels illustrated in FIG.26A is exemplary and tubing can be selected to have any suitablediameters, as the aspects are not limited in this respect. Using thisconfiguration, hydrogen gas can be cooled as it flows through the innertube 2650 of coaxial tubing 2675.

In particular, hydrogen gas flowing through inner tube 2650 transfersheat to PCM contained in middle tube 2660 that has been chilled to itslow temperature state via chilled coolant flowing through outer tube2670. For example, coolant may be chilled to a temperature sufficient tocause a state transition of the PCM to its low temperature state usingany of the refrigeration techniques discussed herein and thereafterpumped through outer tube 2670 to chill the PCM to cause a statetransition. According to some embodiments, coolant from a coolantreservoir that has been chilled to a desired temperature by arefrigeration unit may be pumped through outer tube 2670 to cause thePCM to change state and then circulated back to the reservoir fortemperature recovery. As discussed above, once the PCM has been chilledto its low temperature state, heat absorbed from hydrogen flowingthrough inner tube 2650 will go into transitioning the PCM to itsambient temperature state rather than heating the PCM. As a result,chilled coolant may only need to be pumped through outer tube 2670 whenthe PCM has substantially transitioned to its ambient temperature stateor when the fueling system determines that the low temperature state ofthe PCM should be fully recovered.

FIG. 26B illustrates a hydrogen fueling system in which coaxial tubingis employed to provide chilled hydrogen to one or more dispensers fordelivery to a fuel tank of an HFCV during a fueling event. In theembodiment illustrated in FIG. 26B, hydrogen fueling system 1600comprises hydrogen gas source 2605, chiller system 2612 and one or moredispensers 2620. Coaxial tubing 2675 is fluidly coupled to components ofthe chiller system 2612 to dispenser(s) 2620 to provide chilled hydrogenfor dispensing. Coaxial tubing 2675 may also be employed to transporthydrogen directly from hydrogen source 2605 to the one or moredispensers, as discussed in further detail below. Chiller system 2612may include any combination of refrigeration unit and coolant reservoirdescribed herein and may employ any of the cooling techniques discussedabove to provide chilled coolant to outer tube 2660 of coaxial tubing2675 at a sufficiently low temperature to cause PCM contained in middletube 2660 to transition to its low temperature state. Heated coolant maybe returned to chiller system 2612 via a return line (not shown) or anysuitable return path. The chilled PCM absorbs heat from hydrogen gasfrom the hydrogen gas source 2605 as it flows through inner tube 2650 ofcoaxial tubing 2675 to deliver chilled hydrogen to dispenser(s) 2620.

According to some embodiments, chiller system 2612 also comprises a heatexchanger that pre-cools hydrogen gas from hydrogen gas source 2605before being provided to coaxial tubing 2675. In embodiments employing aheat exchanger, the heat transfer load of chilling hydrogen gas may beshared between the heat exchanger and coaxial tubing 2675 so that alower UA heat exchanger can be employed at reduced cost relative toembodiments of high UA exchangers discussed herein. As discussed inconnection with the other PCM techniques discussed above, use of PCM ina coaxial tubing facilitates increasing back-to-back fills, reducing thesize and cost of components of the hydrogen cooling system, or somecombination of each. According to some embodiments, coaxial tubing 2675may be used to transport hydrogen gas from hydrogen gas source 2605(e.g., one or more storage tanks) to the one or more dispensers andchiller system 2612 may be coupled at the connection of the coaxialtubing to the hydrogen gas source so that hydrogen cooling may beperformed via a direct transport link between the hydrogen gas source2650 and the one or more dispensers. Coaxial tubing 2675 may be used toconnect components of a hydrogen fueling station in other ways, as theuse of coaxial tubing is not limited to any particular arrangement.

As discussed above, a fueling event includes a dispenser at a hydrogenfueling station delivering hydrogen from a hydrogen source at thefueling station to a fuel tank onboard a HFCV. When the nozzle of thedispenser is engaged with the vehicle fuel tank, the dispenser isactivated to control the flow of hydrogen into the fuel tank of thevehicle. As discussed above, tank parameters such as tank pressure, tankvolume, tank temperature, etc. are typically communicated to thedispenser so that the dispenser can safely refill the tank. Fuelingprotocols are established for safely refueling a HFCV and dispensers areconfigured to control the flow of gas into the tank according to acorresponding fueling protocol. FIG. 27 illustrates a typical fuelingprotocol for an HFCV. During a startup up time, the dispenser deliversgas to perform certain start actions. After the start-up time, thedispenser will enter an active filling stage in which the dispenserattempts to maintain a constant pressure ramp rate to the vehicle asillustrated by the linear ramp of the pressure profile between the startand end of fueling points of the exemplary fueling protocol illustratedin FIG. 27, which is interrupted by two dwell time safety checks inwhich the dispenser is required to stop the flow of hydrogen to ensurethere is no leaking. Fueling protocols typically specify a tolerance(referred to as the pressure corridor) that a dispenser is allowed todeviate from the specified pressure profile of the fueling protocol(e.g., between +7 MPa/min and −2 MPA/min from the target pressureprofile of the fueling protocol. Thus, hydrogen fueling involvescontrolling the dispenser to maintain a constant pressure ramp (e.g.,bar per minute) as opposed to maintain a particular mass flow rate(e.g., kg per minute). Because hydrogen is compressible, the mass flowrate of the hydrogen is not constant. According, the dispenser must beable to control vary the area through which hydrogen gas flows to allowthe mass flow rate to vary to maintain the desired pressure profile ofthe fueling protocol. Some fueling protocols may provide target hydrogenflow rates instead of or in addition to target pressures.

The inventors have developed dispenser techniques to facilitatedispenser control of hydrogen gas to a fuel tank of a HFCV. According tosome embodiments, a dispenser comprises a bank of fixed-sized orificevalves that can be turned off and on in any desired combination tocontrol the mass flow rate of hydrogen gas to the vehicle to achieve thepressure profile (e.g., a constant pressure ramp) of a fueling protocol.According to some embodiments, a variable-size orifice solenoid valvepaired to a direct drive servo motor is employed to control the massflow rate of hydrogen to match the pressure profile of a correspondingfueling protocol. As discussed above, either the fixed-sized orificesolution or the variable-size orifice solution can be employed in any ofthe dispenser illustrated above in connection with the exemplary fuelingstations.

FIG. 28 illustrates a fixed-orifice dispenser comprising a valve bank offixed-size orifice valves that can be controlled to be open or closed toprovide a desired flow area to achieve a target pressure and/or targetflow rate during a fueling event, in accordance with some embodiments.As used herein, a fixed-size orifice valve refers to an orifice having afixed-size opening or flow area paired with a valve that can be openedor closed. According to some embodiments, a valve bank may include oneor more fixed-size orifices that are not paired with a valve. Forexample, in addition to one or more fixed-size orifice valves, a valvebank may include one or more fixed-size orifices such that when adispenser is enabled to dispense hydrogen gas (e.g., by opening a mastervalve to the valve bank) a minimum flow rate of hydrogen will bedelivered to the nozzle via the one or more fixed-size orifices withoutneeding to open a respective associated valve.

In the embodiment illustrated in FIG. 28, exemplary dispenser 2820comprises valve bank 2880 that includes a plurality of fixed-sizeorifice valves 2885 a-2885 e arranged in parallel that can be turned onand off under control of dispenser controller 2890. As used herein,arranged in parallel means that the same hydrogen gas does not flowthrough any of the fixed-size orifice valves that are so arranged. As aresult, the hydrogen gas provided at output 2880 b is the sum of thehydrogen gas flowing through the fixed-size orifice valves that arearranged in parallel. A supply of hydrogen gas, either from a hydrogengas source directly for ambient fills or in configurations in whichhydrogen cooling is performed downstream of valve bank 2880, or via ahydrogen cooling system (e.g., any of the exemplary hydrogen coolingsystem described herein) in configurations in which hydrogen cooling isperformed upstream of valve bank 2880, is provided to a main fuel valve,which is turned on when dispenser nozzle 2825 is engaged with the fueltank interface 2811 of HFCV 2810 to provide hydrogen gas at input 2880 aof bank 2880. The flow of hydrogen gas is governed by which of the fixedorifice valves the controller opens to pass hydrogen gas from the supplyto the dispenser nozzle 2825 and into the fuel tank of the HFCV.

According to some embodiments, dispenser controller 2890 is configuredto control the pressure of hydrogen gas dispensed to the HFCV, forexample, according to a pressure profile of a hydrogen fueling protocol.Thus, dispenser controller receives the target pressure 2892 (or targetflow rate) indicative of the desired tank pressure of the fuel tank ofHFCV (or target flow rate to the tank) at a given instant during thefueling event, which target pressure and/or target flow rate may varyover the course of the fueling event in accordance with the fuelingprotocol. To achieve the desired pressure, controller 2890 may beconfigured to receive the supply pressure 2891 of the hydrogen gas fromthe gas supply, a measured pressure downstream of the valve bank and/orthe tank pressure of the fuel tank of the HFCV. As discussed above, tankparameters may be received via a communications link established betweenthe nozzle and the fuel tank, via a communications link establishedbetween the vehicle and a fueling station network and/or or may bereceived via other means (e.g., tank pressure may be measured directlyby nozzle 2825). Thus, controller 2890 may receive the tank pressure2893 at a given instant in time. Using the supply pressure 2891 andeither the measured pressure 2894, the tank pressure 2893, or both, andthe known pressure differential across each of the fixed orifices,controller 2890 determines which combination of fixed orifices valves2885 a-e should be opened to provide a hydrogen gas flow rate that mostclosely matches the hydrogen gas flow rate that will deliver the targetpressure 2892 (or target flow rate) to the tank (e.g., a constantpressure ramp during the course of the fueling event). Controller 2890may also receive measurements from one or more sensors 2870 to ensurethat the dispenser is delivering the desired flow rate of hydrogen gas.For example, sensor(s) 2870 may include a pressure sensor, a mass flowrate sensor or both as a check to make sure that the hydrogen gas isbeing delivered as intended.

It should be appreciated that bank 2880 may include any number offixed-size orifice valves of any size. For example, bank 2880 mayinclude a plurality of orifices at different fixed sizes, a plurality oforifices at a same size or any combination of different and same sizeorifices to achieve the desired granularity in control over the flowrate of hydrogen between the hydrogen supply and the dispenser nozzle.Fixed-size orifice valves are relatively inexpensive and have few movingparts and therefore can provide a cost effective and reliable dispensersolution for dispensing hydrogen gas to a HFCV vehicle. Additionally,valve bank 2880 may include one or more fixed-size orifices without anassociated valve that allows hydrogen flow whenever supply hydrogen isprovided to the valve bank 2880 (e.g., whenever the main fuel valve ofthe dispenser is opened), some examples of which are described infurther detail below in connection with FIG. 30.

FIG. 29 illustrates a method of controlling hydrogen gas flow during afueling event using a valve bank containing a plurality of fixed-sizeorifice valves arranged in parallel, in accordance with someembodiments. In act 2910, a fueling event may begin when, for example, anozzle at a dispenser is engaged with the fuel tank of a vehicle or afuel event is otherwise initiated. According to some embodiments,vehicle-to-nozzle pairing is performed during act 2910 using any of thetechniques discussed herein, or vehicle-to-nozzle pairing may beperformed using conventional techniques (e.g., via IrDA when thedispenser nozzle is engaged with the vehicle). In act 2920, thedispenser is prepared to perform the fueling event and may includereceiving tank parameters from the vehicle, engaging relevant portionsof a hydrogen cooling system to provide chilled hydrogen gas, opening amaster valve to allow hydrogen gas from the supply (e.g., hydrogen gasstored in a bank of storage tanks) to flow to the dispenser (e.g., astop flow valve of the valve bank of the dispenser), obtaining a fuelingprotocol for the fueling event or any other tasks to prepare thedispenser to perform the fueling event. According to some embodiments,components of a hydrogen cooling system are arranged upstream from thedispenser so that chilled hydrogen is supplied to the dispenser. In someembodiments, one or more components of a hydrogen cooling system (e.g.,a heat exchanger) are provided downstream from the dispenser flowcontrol system (e.g., downstream of the valve bank) prior to beingdelivered to the nozzle so that the dispenser is supplied hydrogen gasat approximately the temperature at which the hydrogen gas is stored. Tobegin fueling, the dispenser controller may be configured to allow aprescribed amount of hydrogen to flow through the dispenser for deliveryto the fuel tank of the vehicle via the nozzle during a start-up period.

In act 2930, the dispenser controller receives or obtains input from oneor more sensors or otherwise receiving information for the fuelingevent. For example, the dispenser may be configured to receive supplypressure of the hydrogen gas at the input of the dispenser, measuredpressure and/or flow rate downstream of the valve bank and/or tankpressure of the fuel tank of the vehicle, and a target pressure of thefuel tank (or a flow rate to the tank) that the dispenser controllerseeks to achieve. As discussed in the foregoing, the target pressureand/or hydrogen flow rate may be obtained from a fueling protocol thatprovides a pressure profile the dispenser should follow during therefueling event. The dispenser controller may also obtain other inputsuch as hydrogen flow rate at or near the nozzle (e.g., downstream fromthe dispenser valve system), temperature or other input in connectionwith the fueling event.

In act 2940, the dispenser controller controls the plurality offixed-sized orifice valves based on the input received by the dispensercontroller including, but not limited to, opening one or more of theplurality of fixed-size orifice valves, closing one or more of theplurality of fixed-size orifice valves, or maintaining the existingcombination of open and closed fixed-sized orifice valves to deliverhydrogen flow through the valve bank that matches the target pressureand/or target flow rate or follows the target pressure profile asclosely as possible. According to some embodiments, the dispensercontroller uses the supply pressure of hydrogen gas at or near the inputto the valve bank (upstream of the valve bank), the measured pressureand/or flow rate downstream of the valve bank and/or the current tankpressure of the fuel tank of the vehicle, and the current targetpressure and/or hydrogen flow rate to determine the combination of openand closed fixed-size orifice valves that will deliver hydrogen at aflow rate that will result in bringing the measured pressure or tankpressure towards the target pressure or the target flow, respectively.For example, the dispenser controller may use the difference between themeasured pressure and/or current tank pressure and the current targetpressure to selectively open or close one or more of the fixed-sizeorifice valves or maintain the current combination of open and closedvalves to minimize the difference between the current tank pressure andthe current target pressure. However, the dispenser controller candetermine the combination of open and closed fixed-size orifice valvesin other suitable ways to follow a target pressure and/or flow rateprofile for the fueling event. The dispenser controller may beconfigured to continuously monitor the input received (e.g., received inact 2930) to control the valve bank to adjust the hydrogen flow rate tofollow the target pressure and/or flow rate profile for the fuelingevent until the fill is complete (act 2945).

A fill may be completed when the nozzle is disengaged from the fueltank, the dispenser determines that the fuel tank is full (e.g., thetank pressure has reached its maximum tank pressure), or the dispenserotherwise determines that the delivery of hydrogen gas should beterminated. To end the fueling event (act 2950), the dispensercontroller may close the master valve (e.g., stop flow valve) to thevalve bank, close the plurality of fixed-sized orifice valves, orotherwise stop the dispensing of hydrogen gas to the fuel tank of thevehicle. By using the supply pressure, measured pressure and/or currenttank pressure and target pressure and/or target flow rate to control thefueling event, the dispenser can perform a fueling event according to adesired fueling protocol to the resolution of the valve bank based onthe number of valves and/or combination of different orifice sizes,which can be designed to achieve a desired granularity in different flowrates.

FIG. 30 illustrates a hydrogen fueling system comprising a dispenserutilizing a valve bank of fixed-size orifice valves implementing adual-nozzle configuration, in accordance with some embodiments. Hydrogenfueling system 3000 comprises a dispenser 3020 that controls flow ofhydrogen gas to a pair of nozzles configured for performing fuelingevents for two different types of vehicles. According to someembodiments, dispenser 3020 may be configured with two separate flowpaths to deliver hydrogen gas to nozzle 3025 a configured for use with afirst type of vehicle (e.g., cargo trucks, etc.) and to deliver hydrogengas to nozzle 3025 b configured for use with a second type of vehicle(e.g., passenger busses). It should be appreciated that the dual nozzleconfiguration can be configured to deliver hydrogen to any type ofvehicle, as the aspects are not limited in this respect.

In the embodiment illustrated in FIG. 30, valve bank 3080 comprisesfixed-size orifice valves 3085 a and 3085 b, fixed-size orifice 3084 andfull flow valve 3083. According to one example configuration, the sizeof the orifice for fixed-size orifice valve 3085 a may be 0.038 inches(allowing 750 grams/min of flow) and the size of the orifices forfixed-size orifice valve 3085 b and fixed-size orifice 3084 may both be0.022 inches (allowing 250 grams/min of flow). However, these values aremerely exemplary and any size orifices may be chosen depending on therequirements of the dispenser. In the embodiment illustrated in FIG. 30,nozzles 3025 a and 3025 b may have an associated nozzle fixed-sizeorifice valve 3085 c and 3085 d, respectively, that are sized accordingto the type of vehicle that the nozzle is configured to refuel to allowa maximum flow rate to be delivered to the nozzle. According to someembodiments, the size of the orifice for fixed-size orifice valve 3085 cmay be 0.058 inches (allowing for a maximum flow rate of 1800 grams/min)and the size of the orifice for fixed-size orifice valve 3085 d may be0.082 inches (allowing for a maximum flow rate of 3600 grams/min).Fixed-size orifice 3084 has no associated valve so that whenever stopflow valve 3005 is opened and one of nozzle valves 3085c, 3085 d isopened, a minimum flow rate dictated by the size of this orifice (e.g.,250 g/min) will be delivered to the corresponding nozzle. Full flowvalve 3083 has no associated orifice so that hydrogen gas will flowthrough the valve bank at full flow and will be limited by the orificeof the nozzle valve of whichever of nozzle 3025 a, 3205 b has beenengaged with a vehicle.

As one example fueling event using this configuration, all of the valvesmay be closed to begin with and the either nozzle valve 3085 c or 3085 dwill be opened depending on which nozzle has been engaged with a vehicleof the corresponding type. According to some embodiments, the nozzlesthemselves are different so that they cannot be mistakenly engaged withthe wrong type of vehicle. When stop flow valve 3005 is opened to beginthe fueling event, hydrogen gas will flow only through orifice 3084 atthe maximum flow rate of the orifice (e.g., 250 g/min). Dispensercontroller 3090 may then select which of fixed-size orifice valves 3085a, 3085 b and/or full flow valve 3083 to open to deliver hydrogen gas atdifferent flow rates ranging from the maximum flow rate of orifice 3084to the maximum flow rate of the nozzle valve 3085 c, 3085 d engaged witha vehicle during the fueling event. For the exemplary orifice sizesdiscussed above, dispenser controller 3090 can deliver a flow rate of250 g/min, 500 g/min, 1000 g/min, 1500 g/min and full flow rate that islimited to 1800 g/min for nozzle 3025 a and that is limited to 3600g/min for nozzle 3025 b. However, it should be appreciated that anynumber of fixed-size orifice valves of any size can be used to deliveredflow rates to any type of desired vehicle, as the aspects thedual-nozzle dispenser configuration are not limited in this respect.

According to some embodiments, a variable-size orifice valve paired to adirect drive servo motor is employed to control the mass flow rate ofhydrogen to match the pressure profile of a corresponding fuelingprotocol. Many conventional hydrogen flow control valves employ pressureregulator valves that are opened and closed pneumatically based on thepressure differential across the valve. Pressure regulator valves arefrequently used in hydrogen fueling applications because there are noelectrical components and are by design safe for hydrogen fuelingenvironments. The inventors recognized that the use of pressureregulator valves have drawbacks, some associated with slow responsetimes to pressure changes at the hydrogen gas supply. Typical hydrogensources at a fueling station comprise a bank of cascaded tanks atdifferent pressures that are successively opened during a fueling event.As a result, the supply pressure will decrease as hydrogen flows fromthe first tank and then will spike each time a successive tank isengaged to deliver hydrogen. Conventional dispenser controllers usingpressure regulator valves typically cannot handle such large changes insupply pressure and as a result are forced to stop the flow of hydrogengas, reset the pressure regulators and then start the flow again. As aresult, hydrogen fueling stations typically must be paired with aspecific dispenser tuned to the specific storage bank at that fuelingstation, resulting in costly, time consuming and inflexible deploymentof a hydrogen dispenser that must be matched to a specific fuelingstation. Some hydrogen gas dispenser utilize stepper motors to open andclose the valve opening, but stepper motor solutions also suffer fromslow response times and lack of control.

According to some embodiments, a variable-size orifice valve is pairedwith a direct drive servo motor providing high resolution and highlyresponsive control over the variable-size orifice valve, therebyaddressing a number of drawbacks of conventional dispensers that utilizevariable-size orifice valves that are paired with stepper motors and/orrely on pressure regulators to control hydrogen flow into the fuel tankof an HFCV during a fueling event. As used herein, a direct drive servomotor refers to a servo motor that has a one-to-one rotationalrelationship with the valve to which it is paired. That is, each 360°rotation of the direct drive servo motor results in a 360° rotation ofthe valve stem. By contrast, stepper motors or other geared motors havea many-to-one rotational relationship with the valve to which it ispaired. That is, a 360° rotation of the valve stem requires multiplerotations of the stepper motor due to gear reduction. For example, atypical stepper motor may have a twenty-to-one rotational relationshipwith the valve so that the stepper motor rotates twenty times (i.e.,7200° of rotation) to effect one rotation of the valve stem (i.e.,360°). As a result, pairing the valve with a direct driver servo motorresults in significantly fast response times. Additionally, direct driveservo motors according to some embodiments can operate at significantlyhigher rotations per minute (RPMs) than stepper motors, furtherincreasing the speed increase and responsive improvement overconventional stepper motor solutions. That is, direct drive servo motorsaccording to some embodiments not only effect more change in the valveopening on each rotation, but also rotate faster.

According to some embodiments, a direct drive servo motor includes anencoder that measures the rotation of the direct drive servo motor.Because the servo motor is direct drive, the encoder allows the positionof the valve to be measured (i.e., how many degrees the valve has beenopened). The measured valve position allows the dispenser controller tooperate in a closed feedback loop, facilitating precise control and fastresponse times at a high degree of resolution. According to someembodiments, the encoder measures rotation with one degree of resolutionor less (0.5 degrees or less, more preferably 0.3 degrees or less, andmore preferably at 0.1 degrees of resolution), allowing the valveposition to be precisely determined. According to some embodiments, theencodes measures rotation down to 0.1 degree of resolution, allowing forhighly precise control.

Hydrogen dispensers employing a flow control valve having a direct driveservo motor paired with variable-size orifice valve and controltechniques described herein provide high resolution and fast responsetimes that allow the dispenser to be deployed at virtually any fuelingstation independent of the characteristics of the hydrogen gas source(e.g., independent of the characteristics of the supply bank),eliminating the need to match and custom tune the dispenser for aspecific hydrogen supply bank or hydrogen source configuration andallowing for the design of standalone hydrogen dispensers that areagnostic to the fueling station configuration and hydrogen supplycharacteristics, facilitating simple cost effective deployment across awide range of different fueling stations. Because the flow control valveusing the direct drive servo motor techniques described herein canrespond quickly and precisely, the dispenser controller does not need tostop flow when a different supply tank is switched to and the dispenserneed not know that specifics of the number, trigger levels or pressurechanges that will result from a particular storage bank because thedispenser controller can respond quickly to pressure spikes and continueto deliver hydrogen gas at the desired pressure.

FIG. 31 illustrates a dispenser employing a flow control valvecomprising a variable-size orifice valve paired with a direct driveservo motor that can be controlled to vary the size of the valve openingto provide a desired flow area that delivers a flow rate that achieves atarget pressure and/or target flow rate during a fueling event, inaccordance with some embodiments. In the embodiment illustrated in FIG.31, exemplary dispenser 3120 employs flow control valve 3100 comprisinga direct drive servo motor 3180 coupled to variable-size valve 3185 tovary the size of the valve opening based on control signals 3195 fromdispenser controller 3190. Dispenser 3120 may also include a stop flowvalve 3105 that is closed to stop hydrogen flow when the dispenser isnot being used and that is opened at the beginning of a fueling event.One or more of the inputs to the dispenser 3120 and dispenser controller3190 may be similar to or the same as those described in connection thedispenser illustrated in FIG. 28. For example, a supply of hydrogen gas,either from a hydrogen gas source directly for ambient fills or inconfigurations in which hydrogen cooling is performed downstream ofvalve 3185, or via a hydrogen cooling system (e.g., any of the exemplaryhydrogen cooling system described herein) in configurations in whichhydrogen cooling is performed upstream of valve 3185 via a hydrogencooling system (e.g., any of the exemplary hydrogen cooling systemdescribed herein), is provided to the dispenser when dispenser nozzle3125 is engaged with the fuel tank interface 3111 of HFCV 3110.

Dispenser controller 3190 may be configured to control the pressure ofhydrogen gas dispensed to the HFCV, for example, according to a pressureprofile of a hydrogen fueling protocol. For example, dispensercontroller 3190 may receive the target pressure and/or target flow rate3192 indicative of the desired tank pressure of the fuel tank of HFCVand/or the desired flow rate to be delivered at a given instant duringthe fueling event, which target pressure and/or target flow rate mayvary over the course of the fueling event in accordance with the fuelingprotocol. To achieve the desired pressure, controller 3190 may beconfigured to receive the supply pressure 3191 of the hydrogen gas fromthe gas supply, a measured pressure and/or measured flow rate downstreamfrom the flow control valve (e.g., measured by a sensor(s) in sensor(s)3170 and/or the tank pressure 3193 of the fuel tank of the HFCV. Asdiscussed above, tank parameters may be received via a communicationslink established between the nozzle and the fuel tank, via acommunications link established between the vehicle and a fuelingstation network and/or or may be received via other means (e.g., tankpressure may be measured directly by nozzle 3125). Thus, dispensercontroller 3190 may receive the tank pressure 3193 at a given instant intime.

In the embodiment illustrated in FIG. 31, direct drive servo motorincludes an encoder that measures valve position 3183 (e.g., how manydegrees the valve has been opened) and provides the valve positionmeasurement 3183 to dispenser controller 3190. Using the supply pressure3191, measured pressure and/or measured flow rate 3194 and/or tankpressure 3193, dispenser controller 3190 determines the flow area thatachieves a hydrogen gas flow rate that will deliver the target pressureand/or target flow rate 3192 to the tank (e.g., a constant pressure rampduring the course of the fueling event). Because the dispensercontroller can determine the current flow area of the valve from thevalve position measurement (e.g., the area of the valve opening may bedetermined from the number of degrees that the valve is opened using theknown valve characteristics), dispenser controller 3190 can providesignal 3195 (e.g., a voltage or current signal) that will cause thedirect drive servo motor 3180 to precisely control valve 3185 to achievethe determined flow area. Controller 3190 may also receive measurementsfrom one or more sensors 3170 to ensure that the dispenser is deliveringthe desired flow rate of hydrogen gas. For example, sensor(s) 3170 mayinclude a pressure sensor (to provide the measured pressure 3194), amass flow rate sensor or both as a check to make sure that the hydrogengas is being delivered as intended (or as part of the control feedbackloop).

FIG. 32 illustrates a method of controlling hydrogen gas flow during afueling event using a variable-size valve paired with a direct driveservo motor, in accordance with some embodiments. Acts 3210 and 3220 mayinclude some or all of the actions described for act 2910 and 2920 inconnection with the fueling method illustrated in FIG. 29. For example,a fueling event may begin (act 3210) when, for example, a nozzle at adispenser is engaged with the fuel tank of a vehicle or a fuel event isotherwise initiated. Vehicle-to-nozzle pairing may be performed usingany suitable technique. In act 3220, the dispenser may be prepared toperform the fueling event by receiving tank parameters from the vehicle,engaging relevant portions of a hydrogen cooling system to providechilled hydrogen gas, opening a master valve (e.g., a stop flow valve)to allow hydrogen gas from the supply (e.g., hydrogen gas stored in abank of storage tanks) to flow to the dispenser, obtaining a fuelingprotocol for the fueling event and/or any other tasks to prepare thedispenser to perform the fueling event.

According to some embodiments, components of a hydrogen cooling systemare arranged upstream from the dispenser so that chilled hydrogen issupplied to the dispenser. In some embodiments, one or more componentsof a hydrogen cooling system (e.g., a heat exchanger) are provideddownstream from the dispenser flow control system (e.g., downstream ofthe variable-size valve) prior to being delivered to the nozzle so thatthe dispenser is supplied hydrogen gas at approximately the temperatureat which the hydrogen gas is stored. To begin fueling, the dispensercontroller may cause the direct drive servo motor to open the valve asmall amount (e.g., bring the valve to an almost closed position) andthen slowly open the valve until an initial target pressure and/ortarget flow rate is achieved. By initially opening the valve slowly,large spikes that could potentially overheat the tank or damagecomponents of the dispenser are prevented. Once the initial targetpressure is reached, the dispenser controller control loop follows adesired pressure and/or target flow rate profile based on input receivedby the dispenser controller in act 3230.

For example, the dispenser may be configured to receive supply pressureof the hydrogen gas at the input of the dispenser, measured pressureand/or flow rate downstream of the flow control valve and/or tankpressure of the fuel tank of the vehicle, a target pressure of the fueltank (or target flow rate to be delivered) that the dispenser controllerseeks to achieve, flow rate and feedback from the direct drive servomotor (e.g., valve position from an encoder). As discussed in theforegoing, the target pressure and/or target flow rate may be obtainedfrom a fueling protocol that provides a pressure and/or flow rateprofile the dispenser should follow during the fueling event. Thedispenser controller may also obtain other input such as the hydrogengas pressure and/or hydrogen flow rate at or near the nozzle (e.g.,downstream from the dispenser valve system), or other input inconnection with the fueling event.

In act 3240, the dispenser controller sends signals to the direct driveservo motor (e.g., voltage or current signals indicative of thedirection and amount that the direct drive servo motor should change thevalve position) based on the input received in act 2930. According tosome embodiments, the dispenser controller uses the supply pressure ofhydrogen gas at or near the valve input, the measured pressuredownstream of the flow control valve and/or current tank pressure of thefuel tank of the vehicle, the current target pressure and/or target flowrate, current flow rate and valve position in a closed feedback loop toadjust the valve position (e.g., via signals from the dispensercontroller to the direct drive servo motor) to deliver hydrogen gas atthe target pressure. As the target pressure and/or target flow changes(e.g., according to a fueling protocol) and/or as the supply pressurechanges, the feedback loop tracks the target pressure and/or flow rateby adjusting the valve position accordingly until it is determined thatthe fill is complete in act 3245, for example, when the nozzle isdisengaged from the fuel tank, the dispenser determines that the fueltank is full (e.g., the tank pressure has reached its maximum tankpressure), or the dispenser otherwise determines (or is instructed) thatthe delivery of hydrogen gas should be terminated. To end the fuelingevent (act 3250), the dispenser controller may signal the direct driveservo motor to bring the valve to a fully closed position (and close anymaster valve that may be present) and/or otherwise stop the dispensingof hydrogen gas to the fuel tank of the vehicle.

FIGS. 33 illustrate view of flow control valve comprising avariable-size valve paired with direct drive servo motor, in accordancewith some embodiments. Exemplary flow control valve 3300 comprises avalve 3330 having a valve opening or orifice 3334 whose size can bevaried from fully closed to fully opened by rotating valve stem 3335. Adirect drive servo motor 3310 is coupled to valve stem 3335 via valvecoupling 3320 so that its rotation causes valve stem 3335 to rotate tochange the size of valve orifice 3334. Hydrogen gas flows through thevalve orifice via inlet 3332a and 3332b. As discussed above, a directdrive servo motor has a one-to-one rotational relationship with valve sothat each 360° rotation of the direct drive servo motor 3310 cause acorresponding 360° rotation of valve stem 3335. According to someembodiments, the valve opening is moved from fully opened to fullyclosed in between 7-10 rotations of the valve stem and the direct driveservo motor is configured to rotate at a speed that moves the valveopening from fully opened to fully closed in between 1 and 5 seconds.For example, according to some embodiments, direct drive servo motor3310 (which may have the ability to rotate at up to 6200 RPM accordingto some embodiments) is configured to rotate at a maximum ofapproximately 200 RPM so that the direct drive servo motor is capable ofcausing valve opening 3334 to move from fully opened to fully closed inapproximately 2 seconds. Because a direct drive servo motor will oftenhave a higher maximum RPM (e.g., 600 RPM, 1200 RPM, 4800 RPM, 6200 RPM,etc.) than the maximum RPM at which the motor will typically be operatedat (e.g., 100 RPM, 200 RPM, 300 RPM, etc.), using a direct drive servomotor allows a variable-size orifice valve to be operated slower orfaster depending on the specific requirements of a dispenser, fuelingprotocol and/or fueling event (e.g., between 1 and 10 seconds, or longerif desired). Compared to conventional control valves that can move avalve opening from fully opened to fully closed on the order of minutes,the ability of a direct drive servo motor to move a valve opening fromfully opened to fully closed on the order of seconds provides forsignificantly faster response times.

For hydrogen fueling applications, a valve that allows for a wide rangeof flow rates is beneficial and, in some cases, may be required.According to some embodiments, a variable-size orifice valve (e.g.,valve 3330 in flow control valve 3300) has a range from 0-90 g/min tofacilitate control of hydrogen flow for hydrogen fueling. For example,some exemplary variable-size orifice valves may be capable of proving 0g/min at the fully closed position and 90 g/min at the fully openedposition. According to some embodiments, a variable-size orifice valvehas a smaller or larger flow rate range (e.g., 0-40 g/min, 0-60 g/min,0-80 g/min, 0-100 g/min, 0-120 g/min, etc), as the aspects are notlimited to any particular range provided the range is suitable forhydrogen fueling. Additionally, the electrical components of the servomotor may be rated for use in hazardous environments to ensure that theelectrical components operate safely in a hydrogen fueling environment.

Having thus described several aspects and embodiments of the technologyset forth in the disclosure, it is to be appreciated that variousalterations, modifications, and improvements will readily occur to thoseskilled in the art. Such alterations, modifications, and improvementsare intended to be within the spirit and scope of the technologydescribed herein. For example, those of ordinary skill in the art willreadily envision a variety of other means and/or structures forperforming the function and/or obtaining the results and/or one or moreof the advantages described herein, and each of such variations and/ormodifications is deemed to be within the scope of the embodimentsdescribed herein. Those skilled in the art will recognize, or be able toascertain using no more than routine experimentation, many equivalentsto the specific embodiments described herein. It is, therefore, to beunderstood that the foregoing embodiments are presented by way ofexample only and that, within the scope of the appended claims andequivalents thereto, inventive embodiments may be practiced otherwisethan as specifically described. In addition, any combination of two ormore features, systems, articles, materials, kits, and/or methodsdescribed herein, if such features, systems, articles, materials, kits,and/or methods are not mutually inconsistent, is included within thescope of the present disclosure.

The above-described embodiments can be implemented in any of numerousways. One or more aspects and embodiments of the present disclosureinvolving the performance of processes or methods may utilize programinstructions executable by a device (e.g., a computer, a processor,controller, or other device) to perform, or control performance of, theprocesses or methods. In this respect, various inventive concepts may beembodied as a computer readable storage medium (or multiple computerreadable storage media) (e.g., a computer memory, one or more floppydiscs, compact discs, optical discs, magnetic tapes, flash memories,circuit configurations in Field Programmable Gate Arrays or othersemiconductor devices, or other tangible computer storage medium)encoded with one or more programs that, when executed on one or morecomputers, controllers or other processors, perform methods thatimplement one or more of the various embodiments described above. Thecomputer readable medium or media can be transportable, such that theprogram or programs stored thereon can be loaded onto one or moredifferent computers or other processors to implement various ones of theaspects described above. In some embodiments, computer readable mediamay be non-transitory media.

The terms “program” or “software” are used herein in a generic sense torefer to any type of computer code or set of computer-executableinstructions that can be employed to program a computer or otherprocessor to implement various aspects as described above. Additionally,it should be appreciated that according to one aspect, one or morecomputer programs that when executed perform methods of the presentdisclosure need not reside on a single computer or processor, but may bedistributed in a modular fashion among a number of different computersor processors to implement various aspects of the present disclosure.

Computer-executable instructions may be in many forms, such as programmodules, executed by one or more computers or other devices. Generally,program modules include routines, programs, objects, components, datastructures, etc. that perform particular tasks or implement particularabstract data types. Typically the functionality of the program modulesmay be combined or distributed as desired in various embodiments.

Also, data structures may be stored in computer-readable media in anysuitable form. For simplicity of illustration, data structures may beshown to have fields that are related through location in the datastructure. Such relationships may likewise be achieved by assigningstorage for the fields with locations in a computer-readable medium thatconvey relationship between the fields. However, any suitable mechanismmay be used to establish a relationship between information in fields ofa data structure, including through the use of pointers, tags or othermechanisms that establish relationship between data elements.

When implemented in software, the software code can be executed on anysuitable processor or collection of processors, whether provided in asingle computer or distributed among multiple computers.

Further, it should be appreciated that a computer may be embodied in anyof a number of forms, such as a rack-mounted computer, a desktopcomputer, a laptop computer, or a tablet computer, as non-limitingexamples. Additionally, a computer may be embedded in a device notgenerally regarded as a computer but with suitable processingcapabilities, including a Personal Digital Assistant (PDA), a smartphoneor any other suitable portable or fixed electronic device.

Also, a computer may have one or more input and output devices. Thesedevices can be used, among other things, to present a user interface.Examples of output devices that can be used to provide a user interfaceinclude printers or display screens for visual presentation of outputand speakers or other sound generating devices for audible presentationof output. Examples of input devices that can be used for a userinterface include keyboards, and pointing devices, such as mice, touchpads, and digitizing tablets. As another example, a computer may receiveinput information through speech recognition or in other audibleformats.

Such computers may be interconnected by one or more networks in anysuitable form, including a local area network or a wide area network,such as an enterprise network, and intelligent network (IN) or theInternet. Such networks may be based on any suitable technology and mayoperate according to any suitable protocol and may include wirelessnetworks, wired networks or fiber optic networks.

Also, as described, some aspects may be embodied as one or more methods.The acts performed as part of the method may be ordered in any suitableway. Accordingly, embodiments may be constructed in which acts areperformed in an order different than illustrated, which may includeperforming some acts simultaneously, even though shown as sequentialacts in illustrative embodiments.

All definitions, as defined and used herein, should be understood tocontrol over dictionary definitions, definitions in documentsincorporated by reference, and/or ordinary meanings of the definedterms.

The indefinite articles “a” and “an,” as used herein in thespecification and in the claims, unless clearly indicated to thecontrary, should be understood to mean “at least one.”

The phrase “and/or,” as used herein in the specification and in theclaims, should be understood to mean “either or both” of the elements soconjoined, i.e., elements that are conjunctively present in some casesand disjunctively present in other cases. Multiple elements listed with“and/or” should be construed in the same fashion, i.e., “one or more” ofthe elements so conjoined. Other elements may optionally be presentother than the elements specifically identified by the “and/or” clause,whether related or unrelated to those elements specifically identified.Thus, as a non-limiting example, a reference to “A and/or B”, when usedin conjunction with open-ended language such as “comprising” can refer,in one embodiment, to A only (optionally including elements other thanB); in another embodiment, to B only (optionally including elementsother than A); in yet another embodiment, to both A and B (optionallyincluding other elements); etc.

As used herein in the specification and in the claims, the phrase “atleast one,” in reference to a list of one or more elements, should beunderstood to mean at least one element selected from any one or more ofthe elements in the list of elements, but not necessarily including atleast one of each and every element specifically listed within the listof elements and not excluding any combinations of elements in the listof elements. This definition also allows that elements may optionally bepresent other than the elements specifically identified within the listof elements to which the phrase “at least one” refers, whether relatedor unrelated to those elements specifically identified. Thus, as anon-limiting example, “at least one of A and B” (or, equivalently, “atleast one of A or B,” or, equivalently “at least one of A and/or B”) canrefer, in one embodiment, to at least one, optionally including morethan one, A, with no B present (and optionally including elements otherthan B); in another embodiment, to at least one, optionally includingmore than one, B, with no A present (and optionally including elementsother than A); in yet another embodiment, to at least one, optionallyincluding more than one, A, and at least one, optionally including morethan one, B (and optionally including other elements); etc.

Also, the phraseology and terminology used herein is for the purpose ofdescription and should not be regarded as limiting. The use of“including,” “comprising,” or “having,” “containing,” “involving,” andvariations thereof herein, is meant to encompass the items listedthereafter and equivalents thereof as well as additional items.

The terms “approximately,” “about,” and “substantially” may be used tomean within ±20% of a target value in some embodiments, within ±10% of atarget value in some embodiments, within ±5% of a target value in someembodiments, and yet within ±2% of a target value in some embodiments.The terms “approximately,” “about,” and “substantially” may include thetarget value.

In the claims, as well as in the specification above, all transitionalphrases such as “comprising,” “including,” “carrying,” “having,”“containing,” “involving,” “holding,” “composed of,” and the like are tobe understood to be open-ended, i.e., to mean including but not limitedto. Only the transitional phrases “consisting of” and “consistingessentially of” shall be closed or semi-closed transitional phrases,respectively.

What is claimed is:
 1. A fueling station comprising: a roadside unitpositioned at the fueling station and configured to communicate with aplurality of on-board units associated with respective vehicles via arespective wireless connection between the roadside unit and each of theplurality of on-board units; and at least one controller coupled to theroadside unit, the at least one controller configured to process fuelinginformation received from the roadside unit via each respective wirelessconnection and configured to cause at least one action to be performedbased on an expected refueling demand determined from the receivedfueling information.
 2. The fueling station of claim 1, wherein at leastone first on-board unit of the plurality of on-board units is withinrange of the roadside unit and the respective wireless connectioncomprises a direct connection established between the roadside unit andthe at least one first on-board unit.
 3. The fueling station of claim 2,wherein at least one second on-board unit of the plurality of on-boardunits is out-of-range of the roadside unit and the respective wirelessconnection comprises an indirect connection established between theroadside unit and the at least one second on-board unit via the at leastone first on-board unit.
 4. The fueling station of claim 1, wherein theat least one controller is configured to cause at least one component ofthe fueling station to be powered down or powered up based on theexpected refueling demand.
 5. The fueling station of claim 1, furthercomprising a hydrogen cooling system, wherein the at least onecontroller is configured to cause at least one component of the hydrogencooling system to be powered down or powered up based on the expectedrefueling demand.
 6. The fueling station of claim 5, wherein thehydrogen cooling system comprises a first refrigeration unit, andwherein the at least one controller is configured to cause operation ofthe first refrigeration unit to be enabled or disabled based on theexpected refueling demand.
 7. The fueling station of claim 6, whereinthe hydrogen cooling system comprises a plurality of refrigeration unitsincluding the first refrigeration unit, and wherein the at least onecontroller is configured to cause operation of more than one of theplurality of refrigeration units to be enabled or disabled based on theexpected refueling demand.
 8. The fueling station of claim 5, whereinthe at least one component comprises one or more refrigeration units,one or more dispensers and/or one or more pumps that are caused to beenabled or disabled based on the expected refueling demand.
 9. A fuelingstation comprising: a roadside unit positioned at the fueling stationand configured to communicate with a first on-board unit associated witha first vehicle via a first wireless connection established between theroadside unit and the on-board unit; at least one controller coupled tothe roadside unit, the at least one controller configured to process anozzle reservation request received by the roadside unit via the firstwireless connection and configured to negotiate a nozzle reservation viathe first wireless connection.
 10. The fueling station of claim 9,wherein the first on-board unit is within range of the roadside unit andthe first wireless connection comprises a direct connection establishedbetween the roadside unit and the first on-board unit.
 11. The fuelingstation of claim 9, wherein the first on-board unit at is out-of-rangeof the roadside unit and the respective wireless connection comprises anindirect connection established between the roadside unit and the firston-board unit via a direct wireless connection established between asecond on-board unit associated with a second vehicle within range ofthe roadside unit.
 12. The fueling station of claim 9, wherein the atleast one controller is configured to determine whether at least onedispenser at the fueling station is capable of fulfilling the nozzlereservation request.
 13. The fueling station of claim 9, wherein the atleast one controller is configured to notify at least one dispenser thatis capable of fulfilling the nozzle reservation of the nozzlereservation.
 14. The fueling station of claim 13, wherein the at leastone controller is configured to identify the at least one dispenser thatis capable of fulfilling the nozzle reservation to the first vehicle viathe first wireless connection.
 15. The fueling station of claim 9,wherein the at least one controller is configured to associate thenozzle reservation with the first wireless connection.
 16. The fuelingstation of claim 15, wherein the at least one controller is configuredto confirm that the first vehicle has the nozzle reservation based onthe association between the nozzle reservation and the first wirelessconnection during vehicle-to-nozzle pairing with the first vehicle. 17.The fueling station of claim 9, wherein the at least one controller isconfigured to provide a nozzle reservation identifier to the firstvehicle via the first wireless connection.
 18. The fueling station ofclaim 17, wherein the at least one controller is configured to confirmthat the first vehicle has the nozzle reservation based on receiving thenozzle reservation identifier during vehicle-to-nozzle pairing with thefirst vehicle.
 19. The fueling station of claim 9, wherein the at leastone controller is configured to negotiate and confirm the nozzlereservation without identification information of the first vehicle orits operator.
 20. The fueling station of claim 9, wherein the at leastone controller is configured to associate the nozzle reservation withidentification information of the first vehicle or its operator receivedby the roadside unit via the first wireless connection, and wherein theat least one controller is configured to confirm that the first vehiclehas the nozzle reservation based on the received identificationinformation.